EDB Postgres™ Advanced Server Guide

 

 

EDB Postgres™ Advanced Server 11

November 20, 2018

 

1 Introduction

This guide describes the features of EDB Postgres Advanced Server (Advanced Server).

Advanced Server adds extended functionality to the open-source PostgreSQL database. The extended functionality supports database administration, enhanced SQL capabilities, database and application security, performance monitoring and analysis, and application development utilities. This guide documents those features that are exclusive to Advanced Server:

•	Enhanced Compatibility Features. Chapter 2 provides an overview of compatibility features supported by Advanced Server.

•	Database Administration. Chapter 3 contains information about features and tools that are helpful to the database administrator.

Index Advisor described in Section 3.2 helps to determine the additional indexes needed on tables to improve application performance.

SQL Profiler described in Section 3.3 locates and diagnoses poorly running SQL queries in applications.

pgsnmpd described in Section 3.4 is an SNMP agent that returns hierarchical monitoring information regarding the current state of Advanced Server.

•	Security. Chapter 4 contains information about security features supported by Advanced Server.

SQL/Protect described in Section 4.1 provides protection against SQL injection attacks.

Virtual Private Database described in Section 4.2 provides fine-grained, row level access.

sslutils described in Section 4.3 provides SSL certificate generation functions.

Data redaction described in Section 4.4 provides protection against sensitive data exposure.

•	EDB Resource Manager. Chapter 5 contains information about the EDB Resource Manager feature, which provides the capability to control system resource usage by Advanced Server processes.

Resource Groups described in Section 5.1 shows how to create and maintain the groups on which resource limits can be defined.

CPU Usage Throttling described in Section 5.2 provides a method to control CPU usage by Advanced Server processes.

Dirty Buffer Throttling described in Section 5.3 provides a method to control the dirty rate of shared buffers by Advanced Server processes.

•	The libpq C Library. The libpq C library described in Chapter 6 is the C application programming interface (API) language for Advanced Server.

•	The PL Debugger. The PL Debugger described in Chapter 7 is a graphically oriented debugging tool for PL/pgSQL.

•	Performance Analysis and Tuning. Chapter 8 contains the various tools for analyzing and improving application and database server performance.

Dynatune described in Section 8.1 provides a quick and easy means for configuring Advanced Server depending upon the type of application usage.

EDB wait states described in Section 8.2 provides a way to capture wait events and other data for performance diagnosis.

•	EDB Clone Schema. Chapter 9 contains information about the EDB Clone Schema feature, which provides the capability to copy a schema and its database objects within a single database or from one database to another database.

•	PL/Java. PL/Java described in Chapter 10 is a package providing access to Java stored functions, procedures, and triggers with the JDBC interface.

•	Enhanced SQL and Other Miscellaneous Features. Chapter 11 contains information on enhanced SQL functionality and other features that provide additional flexibility and convenience.

•	System Catalog Tables. Chapter 12 contains additional system catalog tables added for Advanced Server specific database objects.

•	Advanced Server Keywords. Chapter 13 contains information about the words that Advanced Server recognizes as keywords.

For information about the features that are shared by Advanced Server and PostgreSQL, see the PostgreSQL core documentation, available at:

https://www.postgresql.org/docs/11/static/index.html

 

1.1 What’s New

The following features have been changed in EDB Postgres Advanced Server 10 to create Advanced Server 11:

•	Advanced Server no longer supports the PL/Java package. The PL/Java package is deprecated in EDB Postgres Advanced Server 11 and will be unavailable in EDB Postgres Advanced Server 12. For more information, see Chapter 10.

•	Advanced Server no longer supports the Infinite Cache feature. All related components have been removed such as the functions, scripts, configuration parameters, and columns from statistical tables and views.

•	Advanced Server no longer creates the dbo system catalog in its databases. For more information, see Section 11.3.

•

Advanced Server now supports data redaction, which is a technique for limiting the exposure of sensitive data to certain users. Data redaction results in the alteration of the displayed data to such users. This is accomplished by defining redaction policies for tables with sensitive data. For more information, see Section 4.4.

•	Advanced Server now supports EDB wait states, which is a background worker that probes each running session at a regular interval collecting information such as the database connection, the logged in user, the running query, and the wait events. For more information, see Section 8.2.

•	Advanced Server now permits an infinite number of tries for custom plan generation by setting the edb_custom_plan_tries parameter to -1. For more information, see Section 3.1.3.5.1.

•	The output format of the version() function has been changed to appear more consistent with the PostgreSQL community version output. For more information, see Section 11.2.

•	You can use the edb_filter_log.redact_password_commands extension to instruct the server to redact stored passwords from the log file. For more information, see Section 3.5.7.

1.2 Typographical Conventions Used in this Guide

Certain typographical conventions are used in this manual to clarify the meaning and usage of various commands, statements, programs, examples, etc. This section provides a summary of these conventions.

In the following descriptions a term refers to any word or group of words that may be language keywords, user-supplied values, literals, etc. A term’s exact meaning depends upon the context in which it is used.

•	Italic font introduces a new term, typically, in the sentence that defines it for the first time.

•	Fixed-width (mono-spaced) font is used for terms that must be given literally such as SQL commands, specific table and column names used in the examples, programming language keywords, directory paths and file names, parameter values, etc. For example postgresql.conf, SELECT * FROM emp;

•	Italic fixed-width font is used for terms for which the user must substitute values in actual usage. For example, DELETE FROM table_name;

•	A vertical pipe | denotes a choice between the terms on either side of the pipe. A vertical pipe is used to separate two or more alternative terms within square brackets (optional choices) or braces (one mandatory choice).

•	Square brackets [ ] denote that one or none of the enclosed term(s) may be substituted. For example, [ a | b ], means choose one of “a” or “b” or neither of the two.

•	Braces {} denote that exactly one of the enclosed alternatives must be specified. For example, { a | b }, means exactly one of “a” or “b” must be specified.

•	Ellipses ... denote that the proceeding term may be repeated. For example, [ a | b ] ... means that you may have the sequence, “b a a b a”.

1.3 Other Conventions Used in this Guide

The following is a list of other conventions used throughout this document.

•	This guide applies to both Linux and Windows systems. Directory paths are presented in the Linux format with forward slashes. When working on Windows systems, start the directory path with the drive letter followed by a colon and substitute back slashes for forward slashes.

•

Some of the information in this document may apply interchangeably to the PostgreSQL and EDB Postgres Advanced Server database systems. The term Advanced Server is used to refer to EDB Postgres Advanced Server. The term Postgres is used to generically refer to both PostgreSQL and Advanced Server. When a distinction needs to be made between these two database systems, the specific names, PostgreSQL or Advanced Server are used.

•

The installation directory path of the PostgreSQL or Advanced Server products is referred to as POSTGRES_INSTALL_HOME. For PostgreSQL Linux installations, this defaults to /opt/PostgreSQL/x.x for version 10 and earlier. For later versions, use the PostgreSQL community packages. For Advanced Server Linux installations accomplished using the interactive installer for version 10 and earlier, this defaults to /opt/edb/asx.x. For Advanced Server Linux installations accomplished using an RPM package, this defaults to /usr/edb/asxx. For Advanced Server Windows installations, this defaults to C:\Program Files\edb\asxx. The product version number is represented by x.x or by xx for version 10 and later.

 

1.4 About the Examples Used in this Guide

The examples in this guide are shown in the type and background illustrated below.

Examples and output from examples are shown in fixed-width, blue font on a light blue background.

The examples use the sample tables, dept, emp, and jobhist, created and loaded when Advanced Server is installed.

The tables and programs in the sample database can be re-created at any time by executing the following script:

/usr/edb/asxx/share/pg-sample.sql

where xx is the Advanced Server version number.

In addition there is a script in the same directory containing the database objects created using syntax compatible with Oracle databases. This script file is edb-sample.sql.

The script:

•	Creates the sample tables and programs in the currently connected database.

•	Grants all permissions on the tables to the PUBLIC group.

The tables and programs will be created in the first schema of the search path in which the current user has permission to create tables and procedures. You can display the search path by issuing the command:

SHOW SEARCH_PATH;

You can use PSQL commands to modify the search path.

1.4.1 Sample Database Description

The sample database represents employees in an organization. It contains three types of records: employees, departments, and historical records of employees.

Each employee has an identification number, name, hire date, salary, and manager. Some employees earn a commission in addition to their salary. All employee-related information is stored in the emp table.

The sample company is regionally diverse, so it tracks the locations of its departments. Each company employee is assigned to a department. Each department is identified by a unique department number and a short name. Each department is associated with one location. All department-related information is stored in the dept table.

The company also tracks information about jobs held by the employees. Some employees have been with the company for a long time and have held different positions, received raises, switched departments, etc. When a change in employee status occurs, the company records the end date of the former position. A new job record is added with the start date and the new job title, department, salary, and the reason for the status change. All employee history is maintained in the jobhist table.

The following is the pg-sample.sql script:

SET datestyle TO 'iso, dmy';

 

--

-- Script that creates the 'sample' tables, views

-- functions, triggers, etc.

--

-- Start new transaction - commit all or nothing

--

BEGIN;

--

-- Create and load tables used in the documentation examples.

--

-- Create the 'dept' table

--

CREATE TABLE dept (

deptno NUMERIC(2) NOT NULL CONSTRAINT dept_pk PRIMARY KEY,

dname VARCHAR(14) CONSTRAINT dept_dname_uq UNIQUE,

loc VARCHAR(13)

);

--

-- Create the 'emp' table

--

CREATE TABLE emp (

empno NUMERIC(4) NOT NULL CONSTRAINT emp_pk PRIMARY KEY,

ename VARCHAR(10),

job VARCHAR(9),

mgr NUMERIC(4),

hiredate DATE,

sal NUMERIC(7,2) CONSTRAINT emp_sal_ck CHECK (sal > 0),

comm NUMERIC(7,2),

deptno NUMERIC(2) CONSTRAINT emp_ref_dept_fk

REFERENCES dept(deptno)

);

--

-- Create the 'jobhist' table

--

CREATE TABLE jobhist (

empno NUMERIC(4) NOT NULL,

startdate TIMESTAMP(0) NOT NULL,

enddate TIMESTAMP(0),

job VARCHAR(9),

sal NUMERIC(7,2),

comm NUMERIC(7,2),

deptno NUMERIC(2),

chgdesc VARCHAR(80),

CONSTRAINT jobhist_pk PRIMARY KEY (empno, startdate),

CONSTRAINT jobhist_ref_emp_fk FOREIGN KEY (empno)

REFERENCES emp(empno) ON DELETE CASCADE,

CONSTRAINT jobhist_ref_dept_fk FOREIGN KEY (deptno)

REFERENCES dept (deptno) ON DELETE SET NULL,

CONSTRAINT jobhist_date_chk CHECK (startdate <= enddate)

);

--

-- Create the 'salesemp' view

--

CREATE OR REPLACE VIEW salesemp AS

SELECT empno, ename, hiredate, sal, comm FROM emp WHERE job = 'SALESMAN';

--

-- Sequence to generate values for function 'new_empno'.

--

CREATE SEQUENCE next_empno START WITH 8000 INCREMENT BY 1;

--

-- Issue PUBLIC grants

--

--GRANT ALL ON emp TO PUBLIC;

--GRANT ALL ON dept TO PUBLIC;

--GRANT ALL ON jobhist TO PUBLIC;

--GRANT ALL ON salesemp TO PUBLIC;

--GRANT ALL ON next_empno TO PUBLIC;

--

-- Load the 'dept' table

--

INSERT INTO dept VALUES (10,'ACCOUNTING','NEW YORK');

INSERT INTO dept VALUES (20,'RESEARCH','DALLAS');

INSERT INTO dept VALUES (30,'SALES','CHICAGO');

INSERT INTO dept VALUES (40,'OPERATIONS','BOSTON');

--

-- Load the 'emp' table

--

INSERT INTO emp VALUES (7369,'SMITH','CLERK',7902,'17-DEC-80',800,NULL,20);

INSERT INTO emp VALUES (7499,'ALLEN','SALESMAN',7698,'20-FEB-81',1600,300,30);

INSERT INTO emp VALUES (7521,'WARD','SALESMAN',7698,'22-FEB-81',1250,500,30);

INSERT INTO emp VALUES (7566,'JONES','MANAGER',7839,'02-APR-81',2975,NULL,20);

INSERT INTO emp VALUES (7654,'MARTIN','SALESMAN',7698,'28-SEP-81',1250,1400,30);

INSERT INTO emp VALUES (7698,'BLAKE','MANAGER',7839,'01-MAY-81',2850,NULL,30);

INSERT INTO emp VALUES (7782,'CLARK','MANAGER',7839,'09-JUN-81',2450,NULL,10);

INSERT INTO emp VALUES (7788,'SCOTT','ANALYST',7566,'19-APR-87',3000,NULL,20);

INSERT INTO emp VALUES (7839,'KING','PRESIDENT',NULL,'17-NOV-81',5000,NULL,10);

INSERT INTO emp VALUES (7844,'TURNER','SALESMAN',7698,'08-SEP-81',1500,0,30);

INSERT INTO emp VALUES (7876,'ADAMS','CLERK',7788,'23-MAY-87',1100,NULL,20);

INSERT INTO emp VALUES (7900,'JAMES','CLERK',7698,'03-DEC-81',950,NULL,30);

INSERT INTO emp VALUES (7902,'FORD','ANALYST',7566,'03-DEC-81',3000,NULL,20);

INSERT INTO emp VALUES (7934,'MILLER','CLERK',7782,'23-JAN-82',1300,NULL,10);

--

-- Load the 'jobhist' table

--

INSERT INTO jobhist VALUES (7369,'17-DEC-80',NULL,'CLERK',800,NULL,20,'New Hire');

INSERT INTO jobhist VALUES (7499,'20-FEB-81',NULL,'SALESMAN',1600,300,30,'New Hire');

INSERT INTO jobhist VALUES (7521,'22-FEB-81',NULL,'SALESMAN',1250,500,30,'New Hire');

INSERT INTO jobhist VALUES (7566,'02-APR-81',NULL,'MANAGER',2975,NULL,20,'New Hire');

INSERT INTO jobhist VALUES (7654,'28-SEP-81',NULL,'SALESMAN',1250,1400,30,'New Hire');

INSERT INTO jobhist VALUES (7698,'01-MAY-81',NULL,'MANAGER',2850,NULL,30,'New Hire');

INSERT INTO jobhist VALUES (7782,'09-JUN-81',NULL,'MANAGER',2450,NULL,10,'New Hire');

INSERT INTO jobhist VALUES (7788,'19-APR-87','12-APR-88','CLERK',1000,NULL,20,'New Hire');

INSERT INTO jobhist VALUES (7788,'13-APR-88','04-MAY-89','CLERK',1040,NULL,20,'Raise');

INSERT INTO jobhist VALUES (7788,'05-MAY-90',NULL,'ANALYST',3000,NULL,20,'Promoted to Analyst');

INSERT INTO jobhist VALUES (7839,'17-NOV-81',NULL,'PRESIDENT',5000,NULL,10,'New Hire');

INSERT INTO jobhist VALUES (7844,'08-SEP-81',NULL,'SALESMAN',1500,0,30,'New Hire');

INSERT INTO jobhist VALUES (7876,'23-MAY-87',NULL,'CLERK',1100,NULL,20,'New Hire');

INSERT INTO jobhist VALUES (7900,'03-DEC-81','14-JAN-83','CLERK',950,NULL,10,'New Hire');

INSERT INTO jobhist VALUES (7900,'15-JAN-83',NULL,'CLERK',950,NULL,30,'Changed to Dept 30');

INSERT INTO jobhist VALUES (7902,'03-DEC-81',NULL,'ANALYST',3000,NULL,20,'New Hire');

INSERT INTO jobhist VALUES (7934,'23-JAN-82',NULL,'CLERK',1300,NULL,10,'New Hire');

--

-- Populate statistics table and view (pg_statistic/pg_stats)

--

ANALYZE dept;

ANALYZE emp;

ANALYZE jobhist;

--

-- Function that lists all employees' numbers and names

-- from the 'emp' table using a cursor.

--

CREATE OR REPLACE FUNCTION list_emp() RETURNS VOID

AS $$

DECLARE

v_empno NUMERIC(4);

v_ename VARCHAR(10);

emp_cur CURSOR FOR

SELECT empno, ename FROM emp ORDER BY empno;

BEGIN

OPEN emp_cur;

RAISE INFO 'EMPNO ENAME';

RAISE INFO '----- -------';

LOOP

FETCH emp_cur INTO v_empno, v_ename;

EXIT WHEN NOT FOUND;

RAISE INFO '% %', v_empno, v_ename;

END LOOP;

CLOSE emp_cur;

RETURN;

END;

$$ LANGUAGE 'plpgsql';

--

-- Function that selects an employee row given the employee

-- number and displays certain columns.

--

CREATE OR REPLACE FUNCTION select_emp (

p_empno NUMERIC

) RETURNS VOID

AS $$

DECLARE

v_ename emp.ename%TYPE;

v_hiredate emp.hiredate%TYPE;

v_sal emp.sal%TYPE;

v_comm emp.comm%TYPE;

v_dname dept.dname%TYPE;

v_disp_date VARCHAR(10);

BEGIN

SELECT INTO

v_ename, v_hiredate, v_sal, v_comm, v_dname

ename, hiredate, sal, COALESCE(comm, 0), dname

FROM emp e, dept d

WHERE empno = p_empno

AND e.deptno = d.deptno;

IF NOT FOUND THEN

RAISE INFO 'Employee % not found', p_empno;

RETURN;

END IF;

v_disp_date := TO_CHAR(v_hiredate, 'MM/DD/YYYY');

RAISE INFO 'Number : %', p_empno;

RAISE INFO 'Name : %', v_ename;

RAISE INFO 'Hire Date : %', v_disp_date;

RAISE INFO 'Salary : %', v_sal;

RAISE INFO 'Commission: %', v_comm;

RAISE INFO 'Department: %', v_dname;

RETURN;

EXCEPTION

WHEN OTHERS THEN

RAISE INFO 'The following is SQLERRM : %', SQLERRM;

RAISE INFO 'The following is SQLSTATE: %', SQLSTATE;

RETURN;

END;

$$ LANGUAGE 'plpgsql';

--

-- A RECORD type used to format the return value of

-- function, 'emp_query'.

--

CREATE TYPE emp_query_type AS (

empno NUMERIC,

ename VARCHAR(10),

job VARCHAR(9),

hiredate DATE,

sal NUMERIC

);

--

-- Function that queries the 'emp' table based on

-- department number and employee number or name. Returns

-- employee number and name as INOUT parameters and job,

-- hire date, and salary as OUT parameters. These are

-- returned in the form of a record defined by

-- RECORD type, 'emp_query_type'.

--

CREATE OR REPLACE FUNCTION emp_query (

IN p_deptno NUMERIC,

INOUT p_empno NUMERIC,

INOUT p_ename VARCHAR,

OUT p_job VARCHAR,

OUT p_hiredate DATE,

OUT p_sal NUMERIC

)

AS $$

BEGIN

SELECT INTO

p_empno, p_ename, p_job, p_hiredate, p_sal

empno, ename, job, hiredate, sal

FROM emp

WHERE deptno = p_deptno

AND (empno = p_empno

OR ename = UPPER(p_ename));

END;

$$ LANGUAGE 'plpgsql';

--

-- Function to call 'emp_query_caller' with IN and INOUT

-- parameters. Displays the results received from INOUT and

-- OUT parameters.

--

CREATE OR REPLACE FUNCTION emp_query_caller() RETURNS VOID

AS $$

DECLARE

v_deptno NUMERIC;

v_empno NUMERIC;

v_ename VARCHAR;

v_rows INTEGER;

r_emp_query EMP_QUERY_TYPE;

BEGIN

v_deptno := 30;

v_empno := 0;

v_ename := 'Martin';

r_emp_query := emp_query(v_deptno, v_empno, v_ename);

RAISE INFO 'Department : %', v_deptno;

RAISE INFO 'Employee No: %', (r_emp_query).empno;

RAISE INFO 'Name : %', (r_emp_query).ename;

RAISE INFO 'Job : %', (r_emp_query).job;

RAISE INFO 'Hire Date : %', (r_emp_query).hiredate;

RAISE INFO 'Salary : %', (r_emp_query).sal;

RETURN;

EXCEPTION

WHEN OTHERS THEN

RAISE INFO 'The following is SQLERRM : %', SQLERRM;

RAISE INFO 'The following is SQLSTATE: %', SQLSTATE;

RETURN;

END;

$$ LANGUAGE 'plpgsql';

--

-- Function to compute yearly compensation based on semimonthly

-- salary.

--

CREATE OR REPLACE FUNCTION emp_comp (

p_sal NUMERIC,

p_comm NUMERIC

) RETURNS NUMERIC

AS $$

BEGIN

RETURN (p_sal + COALESCE(p_comm, 0)) * 24;

END;

$$ LANGUAGE 'plpgsql';

--

-- Function that gets the next number from sequence, 'next_empno',

-- and ensures it is not already in use as an employee number.

--

CREATE OR REPLACE FUNCTION new_empno() RETURNS INTEGER

AS $$

DECLARE

v_cnt INTEGER := 1;

v_new_empno INTEGER;

BEGIN

WHILE v_cnt > 0 LOOP

SELECT INTO v_new_empno nextval('next_empno');

SELECT INTO v_cnt COUNT(*) FROM emp WHERE empno = v_new_empno;

END LOOP;

RETURN v_new_empno;

END;

$$ LANGUAGE 'plpgsql';

--

-- Function that adds a new clerk to table 'emp'.

--

CREATE OR REPLACE FUNCTION hire_clerk (

p_ename VARCHAR,

p_deptno NUMERIC

) RETURNS NUMERIC

AS $$

DECLARE

v_empno NUMERIC(4);

v_ename VARCHAR(10);

v_job VARCHAR(9);

v_mgr NUMERIC(4);

v_hiredate DATE;

v_sal NUMERIC(7,2);

v_comm NUMERIC(7,2);

v_deptno NUMERIC(2);

BEGIN

v_empno := new_empno();

INSERT INTO emp VALUES (v_empno, p_ename, 'CLERK', 7782,

CURRENT_DATE, 950.00, NULL, p_deptno);

SELECT INTO

v_empno, v_ename, v_job, v_mgr, v_hiredate, v_sal, v_comm, v_deptno

empno, ename, job, mgr, hiredate, sal, comm, deptno

FROM emp WHERE empno = v_empno;

RAISE INFO 'Department : %', v_deptno;

RAISE INFO 'Employee No: %', v_empno;

RAISE INFO 'Name : %', v_ename;

RAISE INFO 'Job : %', v_job;

RAISE INFO 'Manager : %', v_mgr;

RAISE INFO 'Hire Date : %', v_hiredate;

RAISE INFO 'Salary : %', v_sal;

RAISE INFO 'Commission : %', v_comm;

RETURN v_empno;

EXCEPTION

WHEN OTHERS THEN

RAISE INFO 'The following is SQLERRM : %', SQLERRM;

RAISE INFO 'The following is SQLSTATE: %', SQLSTATE;

RETURN -1;

END;

$$ LANGUAGE 'plpgsql';

--

-- Function that adds a new salesman to table 'emp'.

--

CREATE OR REPLACE FUNCTION hire_salesman (

p_ename VARCHAR,

p_sal NUMERIC,

p_comm NUMERIC

) RETURNS NUMERIC

AS $$

DECLARE

v_empno NUMERIC(4);

v_ename VARCHAR(10);

v_job VARCHAR(9);

v_mgr NUMERIC(4);

v_hiredate DATE;

v_sal NUMERIC(7,2);

v_comm NUMERIC(7,2);

v_deptno NUMERIC(2);

BEGIN

v_empno := new_empno();

INSERT INTO emp VALUES (v_empno, p_ename, 'SALESMAN', 7698,

CURRENT_DATE, p_sal, p_comm, 30);

SELECT INTO

v_empno, v_ename, v_job, v_mgr, v_hiredate, v_sal, v_comm, v_deptno

empno, ename, job, mgr, hiredate, sal, comm, deptno

FROM emp WHERE empno = v_empno;

RAISE INFO 'Department : %', v_deptno;

RAISE INFO 'Employee No: %', v_empno;

RAISE INFO 'Name : %', v_ename;

RAISE INFO 'Job : %', v_job;

RAISE INFO 'Manager : %', v_mgr;

RAISE INFO 'Hire Date : %', v_hiredate;

RAISE INFO 'Salary : %', v_sal;

RAISE INFO 'Commission : %', v_comm;

RETURN v_empno;

EXCEPTION

WHEN OTHERS THEN

RAISE INFO 'The following is SQLERRM : %', SQLERRM;

RAISE INFO 'The following is SQLSTATE: %', SQLSTATE;

RETURN -1;

END;

$$ LANGUAGE 'plpgsql';

--

-- Rule to INSERT into view 'salesemp'

--

CREATE OR REPLACE RULE salesemp_i AS ON INSERT TO salesemp

DO INSTEAD

INSERT INTO emp VALUES (NEW.empno, NEW.ename, 'SALESMAN', 7698,

NEW.hiredate, NEW.sal, NEW.comm, 30);

--

-- Rule to UPDATE view 'salesemp'

--

CREATE OR REPLACE RULE salesemp_u AS ON UPDATE TO salesemp

DO INSTEAD

UPDATE emp SET empno = NEW.empno,

ename = NEW.ename,

hiredate = NEW.hiredate,

sal = NEW.sal,

comm = NEW.comm

WHERE empno = OLD.empno;

--

-- Rule to DELETE from view 'salesemp'

--

CREATE OR REPLACE RULE salesemp_d AS ON DELETE TO salesemp

DO INSTEAD

DELETE FROM emp WHERE empno = OLD.empno;

--

-- After statement-level trigger that displays a message after

-- an insert, update, or deletion to the 'emp' table. One message

-- per SQL command is displayed.

--

CREATE OR REPLACE FUNCTION user_audit_trig() RETURNS TRIGGER

AS $$

DECLARE

v_action VARCHAR(24);

v_text TEXT;

BEGIN

IF TG_OP = 'INSERT' THEN

v_action := ' added employee(s) on ';

ELSIF TG_OP = 'UPDATE' THEN

v_action := ' updated employee(s) on ';

ELSIF TG_OP = 'DELETE' THEN

v_action := ' deleted employee(s) on ';

END IF;

v_text := 'User ' || USER || v_action || CURRENT_DATE;

RAISE INFO ' %', v_text;

RETURN NULL;

END;

$$ LANGUAGE 'plpgsql';

CREATE TRIGGER user_audit_trig

AFTER INSERT OR UPDATE OR DELETE ON emp

FOR EACH STATEMENT EXECUTE PROCEDURE user_audit_trig();

--

-- Before row-level trigger that displays employee number and

-- salary of an employee that is about to be added, updated,

-- or deleted in the 'emp' table.

--

CREATE OR REPLACE FUNCTION emp_sal_trig() RETURNS TRIGGER

AS $$

DECLARE

sal_diff NUMERIC(7,2);

BEGIN

IF TG_OP = 'INSERT' THEN

RAISE INFO 'Inserting employee %', NEW.empno;

RAISE INFO '..New salary: %', NEW.sal;

RETURN NEW;

END IF;

IF TG_OP = 'UPDATE' THEN

sal_diff := NEW.sal - OLD.sal;

RAISE INFO 'Updating employee %', OLD.empno;

RAISE INFO '..Old salary: %', OLD.sal;

RAISE INFO '..New salary: %', NEW.sal;

RAISE INFO '..Raise : %', sal_diff;

RETURN NEW;

END IF;

IF TG_OP = 'DELETE' THEN

RAISE INFO 'Deleting employee %', OLD.empno;

RAISE INFO '..Old salary: %', OLD.sal;

RETURN OLD;

END IF;

END;

$$ LANGUAGE 'plpgsql';

CREATE TRIGGER emp_sal_trig

BEFORE DELETE OR INSERT OR UPDATE ON emp

FOR EACH ROW EXECUTE PROCEDURE emp_sal_trig();

COMMIT;

2 Enhanced Compatibility Features

Advanced Server includes extended functionality that provides compatibility for syntax supported by Oracle applications. Detailed information about all of the compatibility features supported by Advanced Server is provided in the Database Compatibility for Oracle Developers Guides; the information is broken into four guides:

•	The Database Compatibility for Oracle Developers Guide provides an overview of the compatible procedural language, profile management, partitioning syntax, and sample applications supported by Advanced Server.

•	The Database Compatibility for Oracle Developers Tools and Utilities Guide provides information about the compatible tools supported by Advanced Server: EDB*Plus, EDB*Loader, EDB*Wrap, and DRITA.

•	The Database Compatibility for Oracle Developers Built-in Packages Guide provides information about using the compatible syntax available in the built-in packages.

•	The Database Compatibility for Oracle Developers Reference Guide provides reference information about using Advanced Server compatibility features, including SQL syntax, compatible views and system tables, and data types.

Version-specific guides are available at:

https://www.enterprisedb.com/resources/product-documentation

The following sections highlight some of the compatibility features supported by Advanced Server.

2.1 Enabling Compatibility Features

There are several ways to install Advanced Server that will allow you to take advantage of compatibility features:

•	Use the INITDBOPTS variable (in the Advanced Server service configuration file) to specify --redwood-like before initializing your cluster.

•	When invoking initdb to initialize your cluster, include the --redwood-like option.

For more information about the installation options supported by the Advanced Server installers, please see the EDB Postgres Advanced Server Installation Guide, available from the EDB website at:

https://www.enterprisedb.com/resources/product-documentation

2.2 Stored Procedural Language

Advanced Server supports a highly productive procedural language that allows you to write custom procedures, functions, triggers and packages. The procedural language:

•	complements the SQL language and built-in packages.

•	provides a seamless development and testing environment.

•	allows you to create reusable code.

For information about using the Stored Procedural Language, see the Database Compatibility for Oracle Developers Guide, available at:

https://www.enterprisedb.com/resources/product-documentation

2.3 Optimizer Hints

When you invoke a DELETE, INSERT, SELECT, or UPDATE command, the server generates a set of execution plans; after analyzing those execution plans, the server selects a plan that will (generally) return the result set in the least amount of time. The server's choice of plan is dependent upon several factors:

•	The estimated execution cost of data handling operations.

•	Parameter values assigned to parameters in the Query Tuning section of the postgresql.conf file.

•	Column statistics that have been gathered by the ANALYZE command.

As a rule, the query planner will select the least expensive plan. You can use an optimizer hint to influence the server as it selects a query plan.

An optimizer hint is a directive (or multiple directives) embedded in a comment-like syntax that immediately follows a DELETE, INSERT, SELECT or UPDATE command. Keywords in the comment instruct the server to employ or avoid a specific plan when producing the result set. For information about using optimizer hints, see the Database Compatibility for Oracle Developers Guide, available at:

https://www.enterprisedb.com/resources/product-documentation

2.4 Data Dictionary Views

Advanced Server includes a set of views that provide information about database objects in a manner compatible with the Oracle data dictionary views. For detailed information about the views available with Advanced Server, please see the Database Compatibility for Oracle Developers Reference Guide, available at:

https://www.enterprisedb.com/resources/product-documentation

2.5 dblink_ora

dblink_ora provides an OCI-based database link that allows you to SELECT, INSERT, UPDATE or DELETE data stored on an Oracle system from within Advanced Server. For detailed information about using dblink_ora, and the supported functions and procedures, see the Database Compatibility for Oracle Developers Guide, available at:

https://www.enterprisedb.com/resources/product-documentation

2.6 Profile Management

Advanced Server supports compatible SQL syntax for profile management. Profile management commands allow a database superuser to create and manage named profiles. Each profile defines rules for password management that augment password and md5 authentication. The rules in a profile can:

•	count failed login attempts

•	lock an account due to excessive failed login attempts

•	mark a password for expiration

•	define a grace period after a password expiration

•	define rules for password complexity

•	define rules that limit password re-use

A profile is a named set of attributes that allow you to easily manage a group of roles that share comparable authentication requirements. If password requirements change, you can modify the profile to have the new requirements applied to each user that is associated with that profile.

After creating the profile, you can associate the profile with one or more users. When a user connects to the server, the server enforces the profile that is associated with their login role. Profiles are shared by all databases within a cluster, but each cluster may have multiple profiles. A single user with access to multiple databases will use the same profile when connecting to each database within the cluster.

For information about using profile management commands, see the Database Compatibility for Oracle Developers Guide, available at:

https://www.enterprisedb.com/resources/product-documentation

2.7 Built-In Packages

Advanced Server supports a number of built-in packages that provide compatibility with Oracle procedures and functions.

Package Name	Description
DBMS_ALERT	The DBMS_ALERT package provides the capability to register for, send, and receive alerts.
DBMS_AQ	The DBMS_AQ package provides message queueing and processing for Advanced Server.
DBMS_AQADM	The DBMS_AQADM package provides supporting procedures for Advanced Queueing functionality.
DBMS_CRYPTO	The DBMS_CRYPTO package provides functions and procedures that allow you to encrypt or decrypt RAW, BLOB or CLOB data. You can also use DBMS_CRYPTO functions to generate cryptographically strong random values.
DBMS_JOB	The DBMS_JOB package provides for the creation, scheduling, and managing of jobs.
DBMS_LOB	The DBMS_LOB package provides the capability to operate on large objects.
DBMS_LOCK	Advanced Server provides support for the DBMS_LOCK.SLEEP procedure.
DBMS_MVIEW	Use procedures in the DBMS_MVIEW package to manage and refresh materialized views and their dependencies.
DBMS_OUTPUT	The DBMS_OUTPUT package provides the capability to send messages to a message buffer, or get messages from the message buffer.
DBMS_PIPE	The DBMS_PIPE package provides the capability to send messages through a pipe within or between sessions connected to the same database cluster.
DBMS_PROFILER	The DBMS_PROFILER package collects and stores performance information about the PL/pgSQL and SPL statements that are executed during a performance profiling session.
DBMS_RANDOM	The DBMS_RANDOM package provides a number of methods to generate random values. The procedures and functions available in the DBMS_RANDOM package are listed in the following table.
DBMS_RLS	The DBMS_RLS package enables the implementation of Virtual Private Database on certain Advanced Server database objects.
DBMS_SCHEDULER	The DBMS_SCHEDULER package provides a way to create and manage jobs, programs and job schedules.
DBMS_SESSION	Advanced Server provides support for the DBMS_SESSION.SET_ROLE procedure.
DBMS_SQL	The DBMS_SQL package provides an application interface to the EnterpriseDB dynamic SQL functionality.
DBMS_UTILITY	The DBMS_UTILITY package provides various utility programs.
UTL_ENCODE	The UTL_ENCODE package provides a way to encode and decode data.
UTL_FILE	The UTL_FILE package provides the capability to read from, and write to files on the operating system’s file system.
UTL_HTTP	The UTL_HTTP package provides a way to use the HTTP or HTTPS protocol to retrieve information found at an URL.
UTL_MAIL	The UTL_MAIL package provides the capability to manage e-mail.
UTL_RAW	The UTL_RAW package allows you to manipulate or retrieve the length of raw data types.
UTL_SMTP	The UTL_SMTP package provides the capability to send e-mails over the Simple Mail Transfer Protocol (SMTP).
UTL_URL	The UTL_URL package provides a way to escape illegal and reserved characters within an URL.

For detailed information about the procedures and functions available within each package, please see the Database Compatibility for Oracle Developers Built-In Package Guide, available at:

https://www.enterprisedb.com/resources/product-documentation

2.8 Open Client Library

The Open Client Library provides application interoperability with the Oracle Call Interface – an application that was formerly “locked in” can now work with either an Advanced Server or an Oracle database with minimal to no changes to the application code. The EnterpriseDB implementation of the Open Client Library is written in C.

The following diagram compares the Open Client Library and Oracle Call Interface application stacks.

Figure 2.1 – The Open Client Library.

For detailed information about the functions supported by the Open Client Library, see the EDB Postgres Advanced Server OCI Connector Guide, available at:

https://www.enterprisedb.com/resources/product-documentation

2.9 Utilities

For detailed information about the compatible syntax supported by the utilities listed below, see the Database Compatibility for Oracle Developers Tools and Utilities Guide, available at:

https://www.enterprisedb.com/resources/product-documentation

EDB*Plus

EDB*Plus is a utility program that provides a command line user interface to the Advanced Server that will be familiar to Oracle developers and users. EDB*Plus accepts SQL commands, SPL anonymous blocks, and EDB*Plus commands.

EDB*Plus allows you to:

•	Query certain database objects

•	Execute stored procedures

•	Format output from SQL commands

•	Execute batch scripts

•	Execute OS commands

•	Record output

For detailed information about EDB*Plus, please see the EDB*Plus User's Guide.

EDB*Loader

EDB*Loader is a high-performance bulk data loader that provides an interface compatible with Oracle databases for Advanced Server. The EDB*Loader command line utility loads data from an input source, typically a file, into one or more tables using a subset of the parameters offered by Oracle SQL*Loader.

EDB*Loader features include:

•	Support for the Oracle SQL*Loader data loading methods - conventional path load, direct path load, and parallel direct path load

•	Oracle SQL*Loader compatible syntax for control file directives

•	Input data with delimiter-separated or fixed-width fields

•	Bad file for collecting rejected records

•	Loading of multiple target tables

•	Discard file for collecting records that do not meet the selection criteria of any target table

•	Log file for recording the EDB*Loader session and any error messages

•	Data loading from standard input and remote loading

EDB*Wrap

The EDB*Wrap utility protects proprietary source code and programs (functions, stored procedures, triggers, and packages) from unauthorized scrutiny. The EDB*Wrap program translates a file that contains SPL or PL/pgSQL source code (the plaintext) into a file that contains the same code in a form that is nearly impossible to read. Once you have the obfuscated form of the code, you can send that code to Advanced Server and it will store those programs in obfuscated form. While EDB*Wrap does obscure code, table definitions are still exposed.

Everything you wrap is stored in obfuscated form.  If you wrap an entire package, the package body source, as well as the prototypes contained in the package header and the functions and procedures contained in the package body are stored in obfuscated form.

Dynamic Runtime Instrumentation Tools Architecture (DRITA)

The Dynamic Runtime Instrumentation Tools Architecture (DRITA) allows a DBA to query catalog views to determine the wait events that affect the performance of individual sessions or the system as a whole. DRITA records the number of times each event occurs as well as the time spent waiting; you can use this information to diagnose performance problems. DRITA offers this functionality, while consuming minimal system resources.

DRITA compares snapshots to evaluate the performance of a system. A snapshot is a saved set of system performance data at a given point in time. Each snapshot is identified by a unique ID number; you can use snapshot ID numbers with DRITA reporting functions to return system performance statistics.

2.10 ECPGPlus

EnterpriseDB has enhanced ECPG (the PostgreSQL pre-compiler) to create ECPGPlus. ECPGPlus allows you to include embedded SQL commands in C applications; when you use ECPGPlus to compile an application that contains embedded SQL commands, the SQL code is syntax-checked and translated into C.

ECPGPlus supports Pro*C syntax in C programs when connected to an Advanced Server database. ECPGPlus supports:

•	Oracle Dynamic SQL – Method 4 (ODS-M4)

•	Pro*C compatible anonymous blocks

•	A CALL statement compatible with Oracle databases

For information about using ECPGPlus, please see the EDB Postgres Advanced Server ECPG Connector Guide, available from the EnterpriseDB website at:

https://www.enterprisedb.com/resources/product-documentation

2.11 Table Partitioning

In a partitioned table, one logically large table is broken into smaller physical pieces. Partitioning can provide several benefits:

•

Query performance can be improved dramatically in certain situations, particularly when most of the heavily accessed rows of the table are in a single partition or a small number of partitions. Partitioning allows you to omit the partition column from the front of an index, reducing index size and making it more likely that the heavily used parts of the index fits in memory.

•	When a query or update accesses a large percentage of a single partition, performance may improve because the server will perform a sequential scan of the partition instead of using an index and random access reads scattered across the whole table.

•	A bulk load (or unload) can be implemented by adding or removing partitions, if you plan that requirement into the partitioning design. ALTER TABLE is far faster than a bulk operation. It also entirely avoids the VACUUM overhead caused by a bulk DELETE.

•	Seldom-used data can be migrated to less-expensive (or slower) storage media.

Table partitioning is worthwhile only when a table would otherwise be very large. The exact point at which a table will benefit from partitioning depends on the application; a good rule of thumb is that the size of the table should exceed the physical memory of the database server.

For information about database compatibility features supported by Advanced Server see the Database Compatibility for Oracle Developer's Guide, available at:

https://www.enterprisedb.com/resources/product-documentation

3 Database Administration

This chapter describes the features that aid in the management and administration of Advanced Server databases.

3.1 Configuration Parameters

This section describes the database server configuration parameters of Advanced Server. These parameters control various aspects of the database server’s behavior and environment such as data file and log file locations, connection, authentication, and security settings, resource allocation and consumption, archiving and replication settings, error logging and statistics gathering, optimization and performance tuning, locale and formatting settings, and so on.

Most of these configuration parameters apply to PostgreSQL as well. Configuration parameters that apply only to Advanced Server are noted in Section 3.1.2.

Additional information about configuration parameters can be found in the PostgreSQL Core Documentation available at:

https://www.postgresql.org/docs/11/static/runtime-config.html

 

3.1.1 Setting Configuration Parameters

This section provides an overview of how configuration parameters are specified and set.

Each configuration parameter is set using a name/value pair. Parameter names are case-insensitive. The parameter name is typically separated from its value by an optional equals sign (=).

The following is an example of some configuration parameter settings in the postgresql.conf file:

# This is a comment

log_connections = yes

log_destination = 'syslog'

search_path = '"$user", public'

shared_buffers = 128MB

Parameter values are specified as one of five types:

•	Boolean. Acceptable values can be written as on, off, true, false, yes, no, 1, 0, or any unambiguous prefix of these.

•	Integer. Number without a fractional part.

•	Floating Point. Number with an optional fractional part separated by a decimal point.

•	String. Text value. Enclose in single quotes if the value is not a simple identifier or number (that is, the value contains special characters such as spaces or other punctuation marks).

•	Enum. Specific set of string values. The allowed values can be found in the system view pg_settings.enumvals. Enum values are case-insensitive.

Some settings specify a memory or time value. Each of these has an implicit unit, which is kilobytes, blocks (typically 8 kilobytes), milliseconds, seconds, or minutes. Default units can be found by referencing the system view pg_settings.unit. A different unit can be specified explicitly.

Valid memory units are kB (kilobytes), MB (megabytes), and GB (gigabytes). Valid time units are ms (milliseconds), s (seconds), min (minutes), h (hours), and d (days). The multiplier for memory units is 1024.

The configuration parameter settings can be established in a number of different ways:

•

There is a number of parameter settings that are established when the Advanced Server database product is built. These are read-only parameters, and their values cannot be changed. There are also a couple of parameters that are permanently set for each database when the database is created. These parameters are read-only as well and cannot be subsequently changed for the database.

•

The initial settings for almost all configurable parameters across the entire database cluster are listed in the configuration file, postgresql.conf. These settings are put into effect upon database server start or restart. Some of these initial parameter settings can be overridden as discussed in the following bullet points. All configuration parameters have built-in default settings that are in effect if not explicitly overridden.

•	Configuration parameters in the postgresql.conf file are overridden when the same parameters are included in the postgresql.auto.conf file. The ALTER SYSTEM command is used to manage the configuration parameters in the postgresql.auto.conf file.

•

Parameter settings can be modified in the configuration file while the database server is running. If the configuration file is then reloaded (meaning a SIGHUP signal is issued), for certain parameter types, the changed parameters settings immediately take effect. For some of these parameter types, the new settings are available in a currently running session immediately after the reload. For other of these parameter types, a new session must be started to use the new settings. And yet for other parameter types, modified settings do not take effect until the database server is stopped and restarted. See Section 18.1, “Setting Parameters” in the PostgreSQL Core Documentation for information on how to reload the configuration file.

•

The SQL commands ALTER DATABASE, ALTER ROLE, or ALTER ROLE IN DATABASE can be used to modify certain parameter settings. The modified parameter settings take effect for new sessions after the command is executed. ALTER DATABASE affects new sessions connecting to the specified database. ALTER ROLE affects new sessions started by the specified role. ALTER ROLE IN DATABASE affects new sessions started by the specified role connecting to the specified database. Parameter settings established by these SQL commands remain in effect indefinitely, across database server restarts, overriding settings established by the methods discussed in the second and third bullet points. Parameter settings established using the ALTER DATABASE, ALTER ROLE, or ALTER ROLE IN DATABASE commands can only be changed by: a) re-issuing these commands with a different parameter value, or b) issuing these commands using either of the SET parameter TO DEFAULT clause or the RESET parameter clause. These clauses change the parameter back to using the setting established by the methods set forth in the prior bullet points. See Section I, “SQL Commands” of Chapter VI “Reference” in the PostgreSQL Core Documentation for the exact syntax of these SQL commands.

•

Changes can be made for certain parameter settings for the duration of individual sessions using the PGOPTIONS environment variable or by using the SET command within the EDB-PSQL or PSQL command line terminal programs. Parameter settings made in this manner override settings established using any of the methods described by the second, third, and fourth bullet points, but only for the duration of the session.

 

3.1.2 Summary of Configuration Parameters

This section contains a summary table listing all Advanced Server configuration parameters along with a number of key attributes of the parameters.

These attributes are described by the following columns of the summary table:

•	Parameter. Configuration parameter name.

•

Scope of Effect. Scope of effect of the configuration parameter setting. ‘Cluster’ – Setting affects the entire database cluster (that is, all databases managed by the database server instance). ‘Database’ – Setting can vary by database and is established when the database is created. Applies to a small number of parameters related to locale settings. ‘Session’ – Setting can vary down to the granularity of individual sessions. In other words, different settings can be made for the following entities whereby the latter settings in this list override prior ones: a) the entire database cluster, b) specific databases in the database cluster, c) specific roles, d) specific roles when connected to specific databases, e) a specific session.

•

When Takes Effect. When a changed parameter setting takes effect. ‘Preset’ – Established when the Advanced Server product is built or a particular database is created. This is a read-only parameter and cannot be changed. ‘Restart’ – Database server must be restarted. ‘Reload’ – Configuration file must be reloaded (or the database server can be restarted). ‘Immediate’ – Immediately effective in a session if the PGOPTIONS environment variable or the SET command is used to change the setting in the current session. Effective in new sessions if ALTER DATABASE, ALTER ROLE, or ALTER ROLE IN DATABASE commands are used to change the setting.

•

Authorized User. Type of operating system account or database role that must be used to put the parameter setting into effect. ‘EPAS service account’ – EDB Postgres Advanced Server service account (enterprisedb for an installation compatible with Oracle databases, postgres for a PostgreSQL compatible mode installation). ‘Superuser’ – Database role with superuser privileges. ‘User’ – Any database role with permissions on the affected database object (the database or role to be altered with the ALTER command). ‘n/a’ – Parameter setting cannot be changed by any user.

•	Description. Brief description of the configuration parameter.

•	EPAS Only. ‘X’ – Configuration parameter is applicable to EDB Postgres Advanced Server only. No entry in this column indicates the configuration parameter applies to PostgreSQL as well.

Note: There are a number of parameters that should never be altered. These are designated as “Note: For internal use only” in the Description column.

Table 3‑1 - Summary of Configuration Parameters

Parameter	Scope of Effect	When Takes Effect	Authorized User	Description	EPAS Only
allow_system_table_mods	Cluster	Restart	EPAS service account	Allows modifications of the structure of system tables.
application_name	Session	Immediate	User	Sets the application name to be reported in statistics and logs.
archive_command	Cluster	Reload	EPAS service account	Sets the shell command that will be called to archive a WAL file.
archive_mode	Cluster	Restart	EPAS service account	Allows archiving of WAL files using archive_command.
archive_timeout	Cluster	Reload	EPAS service account	Forces a switch to the next xlog file if a new file has not been started within N seconds.
array_nulls	Session	Immediate	User	Enable input of NULL elements in arrays.
authentication_timeout	Cluster	Reload	EPAS service account	Sets the maximum allowed time to complete client authentication.
autovacuum	Cluster	Reload	EPAS service account	Starts the autovacuum subprocess.
autovacuum_analyze_scale_factor	Cluster	Reload	EPAS service account	Number of tuple inserts, updates or deletes prior to analyze as a fraction of reltuples.
autovacuum_analyze_threshold	Cluster	Reload	EPAS service account	Minimum number of tuple inserts, updates or deletes prior to analyze.
autovacuum_freeze_max_age	Cluster	Restart	EPAS service account	Age at which to autovacuum a table to prevent transaction ID wraparound.
autovacuum_max_workers	Cluster	Restart	EPAS service account	Sets the maximum number of simultaneously running autovacuum worker processes.
autovacuum_multixact_freeze_max_age	Cluster	Restart	EPAS service account	Multixact age at which to autovacuum a table to prevent multixact wraparound.
autovacuum_naptime	Cluster	Reload	EPAS service account	Time to sleep between autovacuum runs.
autovacuum_vacuum_cost_delay	Cluster	Reload	EPAS service account	Vacuum cost delay in milliseconds, for autovacuum.
autovacuum_vacuum_cost_limit	Cluster	Reload	EPAS service account	Vacuum cost amount available before napping, for autovacuum.
autovacuum_vacuum_scale_factor	Cluster	Reload	EPAS service account	Number of tuple updates or deletes prior to vacuum as a fraction of reltuples.
autovacuum_vacuum_threshold	Cluster	Reload	EPAS service account	Minimum number of tuple updates or deletes prior to vacuum.
autovacuum_work_mem	Cluster	Reload	EPAS service account	Sets the maximum memory to be used by each autovacuum worker process.
backslash_quote	Session	Immediate	User	Sets whether "\'" is allowed in string literals.
bgwriter_delay	Cluster	Reload	EPAS service account	Background writer sleep time between rounds.
bgwriter_lru_maxpages	Cluster	Reload	EPAS service account	Background writer maximum number of LRU pages to flush per round.
bgwriter_lru_multiplier	Cluster	Reload	EPAS service account	Multiple of the average buffer usage to free per round.
block_size	Cluster	Preset	n/a	Shows the size of a disk block.
bonjour	Cluster	Restart	EPAS service account	Enables advertising the server via Bonjour.
bonjour_name	Cluster	Restart	EPAS service account	Sets the Bonjour service name.
bytea_output	Session	Immediate	User	Sets the output format for bytea.
check_function_bodies	Session	Immediate	User	Check function bodies during CREATE FUNCTION.
checkpoint_completion_target	Cluster	Reload	EPAS service account	Time spent flushing dirty buffers during checkpoint, as fraction of checkpoint interval.
checkpoint_segments	Deprecated in 9.5	Deprecated in 9.5	Deprecated in 9.5	This parameter is not supported by server version 9.5 or later. Specifying a value for the parameter will prevent the server from starting.
checkpoint_timeout	Cluster	Reload	EPAS service account	Sets the maximum time between automatic WAL checkpoints.
checkpoint_warning	Cluster	Reload	EPAS service account	Enables warnings if checkpoint segments are filled more frequently than this.
client_encoding	Session	Immediate	User	Sets the client's character set encoding.
client_min_messages	Session	Immediate	User	Sets the message levels that are sent to the client.
commit_delay	Session	Immediate	Superuser	Sets the delay in microseconds between transaction commit and flushing WAL to disk.
commit_siblings	Session	Immediate	User	Sets the minimum concurrent open transactions before performing commit_delay.
config_file	Cluster	Restart	EPAS service account	Sets the server's main configuration file.
constraint_exclusion	Session	Immediate	User	Enables the planner to use constraints to optimize queries.
cpu_index_tuple_cost	Session	Immediate	User	Sets the planner's estimate of the cost of processing each index entry during an index scan.
cpu_operator_cost	Session	Immediate	User	Sets the planner's estimate of the cost of processing each operator or function call.
cpu_tuple_cost	Session	Immediate	User	Sets the planner's estimate of the cost of processing each tuple (row).
cursor_tuple_fraction	Session	Immediate	User	Sets the planner's estimate of the fraction of a cursor's rows that will be retrieved.
custom_variable_classes	Cluster	Reload	EPAS service account	Deprecated in Advanced Server 9.2.	X
data_checksums	Cluster	Preset	n/a	Shows whether data checksums are turned on for this cluster.
data_directory	Cluster	Restart	EPAS service account	Sets the server's data directory.
DateStyle	Session	Immediate	User	Sets the display format for date and time values.
db_dialect	Session	Immediate	User	Sets the precedence of built-in namespaces.	X
dbms_alert.max_alerts	Cluster	Restart	EPAS service account	Sets maximum number of alerts.	X
dbms_pipe.total_message_buffer	Cluster	Restart	EPAS service account	Specifies the total size of the buffer used for the DBMS_PIPE package.	X
db_user_namespace	Cluster	Reload	EPAS service account	Enables per-database user names.
deadlock_timeout	Session	Immediate	Superuser	Sets the time to wait on a lock before checking for deadlock.
debug_assertions	Cluster	Preset	n/a	Turns on various assertion checks. (Not supported in EPAS builds.)
debug_pretty_print	Session	Immediate	User	Indents parse and plan tree displays.
debug_print_parse	Session	Immediate	User	Logs each query's parse tree.
debug_print_plan	Session	Immediate	User	Logs each query's execution plan.
debug_print_rewritten	Session	Immediate	User	Logs each query's rewritten parse tree.
default_heap_fillfactor	Session	Immediate	User	Create new tables with this heap fillfactor by default.	X
default_statistics_target	Session	Immediate	User	Sets the default statistics target.
default_tablespace	Session	Immediate	User	Sets the default tablespace to create tables and indexes in.
default_text_search_config	Session	Immediate	User	Sets default text search configuration.
default_transaction_deferrable	Session	Immediate	User	Sets the default deferrable status of new transactions.
default_transaction_isolation	Session	Immediate	User	Sets the transaction isolation level of each new transaction.
default_transaction_read_only	Session	Immediate	User	Sets the default read-only status of new transactions.
default_with_oids	Session	Immediate	User	Create new tables with OIDs by default.
default_with_rowids	Session	Immediate	User	Create new tables with ROWID support (OIDs with indexes) by default.	X
dynamic_library_path	Session	Immediate	Superuser	Sets the path for dynamically loadable modules.
dynamic_shared_memory_type	Cluster	Restart	EPAS service account	Selects the dynamic shared memory implementation used.
edb_audit	Cluster	Reload	EPAS service account	Enable EDB Auditing to create audit reports in XML or CSV format.	X
edb_audit_connect	Cluster	Reload	EPAS service account	Audits each successful connection.	X
edb_audit_destination	Cluster	Reload	EPAS service account	Sets edb_audit_directory or syslog as the destination directory for audit files.	X
edb_audit_directory	Cluster	Reload	EPAS service account	Sets the destination directory for audit files.	X
edb_audit_disconnect	Cluster	Reload	EPAS service account	Audits end of a session.	X
edb_audit_filename	Cluster	Reload	EPAS service account	Sets the file name pattern for audit files.	X
edb_audit_rotation_day	Cluster	Reload	EPAS service account	Automatic rotation of log files based on day of week.	X
edb_audit_rotation_seconds	Cluster	Reload	EPAS service account	Automatic log file rotation will occur after N seconds.	X
edb_audit_rotation_size	Cluster	Reload	EPAS service account	Automatic log file rotation will occur after N Megabytes.	X
edb_audit_statement	Cluster	Reload	EPAS service account	Sets the type of statements to audit.	X
edb_audit_tag	Session	Immediate	User	Specify a tag to be included in the audit log.	X
edb_connectby_order	Session	Immediate	User	Sort results of CONNECT BY queries with no ORDER BY to depth-first order. Note: For internal use only.	X
edb_custom_plan_tries	Session	Immediate	User	Specifies the number of custom execution plans considered by the planner before the planner selects a generic execution plan.	X
edb_data_redaction	Session	Immediate	User	Enable data redaction.	X
edb_dynatune	Cluster	Restart	EPAS service account	Sets the edb utilization percentage.	X
edb_dynatune_profile	Cluster	Restart	EPAS service account	Sets the workload profile for dynatune.	X
edb_enable_pruning	Session	Immediate	User	Enables the planner to early-prune partitioned tables.	X
edb_log_every_bulk_value	Session	Immediate	Superuser	Sets the statements logged for bulk processing.	X
edb_max_resource_groups	Cluster	Restart	EPAS service account	Specifies the maximum number of resource groups for simultaneous use.	X
edb_max_spins_per_delay	Cluster	Restart	EPAS service account	Specifies the number of times a session will spin while waiting for a lock.	X
edb_redwood_date	Session	Immediate	User	Determines whether DATE should behave like a TIMESTAMP or not.	X
edb_redwood_greatest_least	Session	Immediate	User	Determines how GREATEST and LEAST functions should handle NULL parameters.	X
edb_redwood_raw_names	Session	Immediate	User	Return the unmodified name stored in the PostgreSQL system catalogs from Redwood interfaces.	X
edb_redwood_strings	Session	Immediate	User	Treat NULL as an empty string when concatenated with a text value.	X
edb_resource_group	Session	Immediate	User	Specifies the resource group to be used by the current process.	X
edb_sql_protect.enabled	Cluster	Reload	EPAS service account	Defines whether SQL/Protect should track queries or not.	X
edb_sql_protect.level	Cluster	Reload	EPAS service account	Defines the behavior of SQL/Protect when an event is found.	X
edb_sql_protect.max_protected_relations	Cluster	Restart	EPAS service account	Sets the maximum number of relations protected by SQL/Protect per role.	X
edb_sql_protect.max_protected_roles	Cluster	Restart	EPAS service account	Sets the maximum number of roles protected by SQL/Protect.	X
edb_sql_protect.max_queries_to_save	Cluster	Restart	EPAS service account	Sets the maximum number of offending queries to save by SQL/Protect.	X
edb_stmt_level_tx	Session	Immediate	User	Allows continuing on errors instead of requiring a transaction abort.	X
edb_wait_states.directory	Cluster	Restart	EPAS service account	The EDB wait states logs are stored in this directory.	X
edb_wait_states.retention_period	Cluster	Restart	EPAS service account	EDB wait state log files will be automatically deleted after retention period.	X
edb_wait_states.sampling_interval	Cluster	Reload	EPAS service account	The interval between two EDB wait state sampling cycles.	X
edbldr.empty_csv_field	Session	Immediate	Superuser	Specifies how EDB*Loader handles empty strings.	X
effective_cache_size	Session	Immediate	User	Sets the planner's assumption about the size of the disk cache.
effective_io_concurrency	Session	Immediate	User	Number of simultaneous requests that can be handled efficiently by the disk subsystem.
enable_bitmapscan	Session	Immediate	User	Enables the planner's use of bitmap-scan plans.
enable_hashagg	Session	Immediate	User	Enables the planner's use of hashed aggregation plans.
enable_hashjoin	Session	Immediate	User	Enables the planner's use of hash join plans.
enable_hints	Session	Immediate	User	Enable optimizer hints in SQL statements.	X
enable_indexonlyscan	Session	Immediate	User	Enables the planner’s use of index-only-scan plans.
enable_indexscan	Session	Immediate	User	Enables the planner's use of index-scan plans.
enable_material	Session	Immediate	User	Enables the planner's use of materialization.
enable_mergejoin	Session	Immediate	User	Enables the planner's use of merge join plans.
enable_nestloop	Session	Immediate	User	Enables the planner's use of nested-loop join plans.
enable_seqscan	Session	Immediate	User	Enables the planner's use of sequential-scan plans.
enable_sort	Session	Immediate	User	Enables the planner's use of explicit sort steps.
enable_tidscan	Session	Immediate	User	Enables the planner's use of TID scan plans.
escape_string_warning	Session	Immediate	User	Warn about backslash escapes in ordinary string literals.
event_source	Cluster	Restart	EPAS service account	Sets the application name used to identify PostgreSQL messages in the event log.
exit_on_error	Session	Immediate	User	Terminate session on any error.
external_pid_file	Cluster	Restart	EPAS service account	Writes the postmaster PID to the specified file.
extra_float_digits	Session	Immediate	User	Sets the number of digits displayed for floating-point values.
from_collapse_limit	Session	Immediate	User	Sets the FROM-list size beyond which subqueries are not collapsed.
fsync	Cluster	Reload	EPAS service account	Forces synchronization of updates to disk.
full_page_writes	Cluster	Reload	EPAS service account	Writes full pages to WAL when first modified after a checkpoint.
geqo	Session	Immediate	User	Enables genetic query optimization.
geqo_effort	Session	Immediate	User	GEQO: effort is used to set the default for other GEQO parameters.
geqo_generations	Session	Immediate	User	GEQO: number of iterations of the algorithm.
geqo_pool_size	Session	Immediate	User	GEQO: number of individuals in the population.
geqo_seed	Session	Immediate	User	GEQO: seed for random path selection.
geqo_selection_bias	Session	Immediate	User	GEQO: selective pressure within the population.
geqo_threshold	Session	Immediate	User	Sets the threshold of FROM items beyond which GEQO is used.
gin_fuzzy_search_limit	Session	Immediate	User	Sets the maximum allowed result for exact search by GIN.
hba_file	Cluster	Restart	EPAS service account	Sets the server's "hba" configuration file.
hot_standby	Cluster	Restart	EPAS service account	Allows connections and queries during recovery.
hot_standby_feedback	Cluster	Reload	EPAS service account	Allows feedback from a hot standby to the primary that will avoid query conflicts.
huge_pages	Cluster	Restart	EPAS service account	Use of huge pages on Linux.
icu_short_form	Database	Preset	n/a	Shows the ICU collation order configuration.	X
ident_file	Cluster	Restart	EPAS service account	Sets the server's "ident" configuration file.
ignore_checksum_failure	Session	Immediate	Superuser	Continues processing after a checksum failure.
ignore_system_indexes	Cluster/ Session	Reload/ Immediate	EPAS service account/ User	Disables reading from system indexes. (Can also be set with PGOPTIONS at session start.)
index_advisor.enabled	Session	Immediate	User	Enable Index Advisor plugin.	X
integer_datetimes	Cluster	Preset	n/a	Datetimes are integer based.
IntervalStyle	Session	Immediate	User	Sets the display format for interval values.
join_collapse_limit	Session	Immediate	User	Sets the FROM-list size beyond which JOIN constructs are not flattened.
krb_caseins_users	Cluster	Reload	EPAS service account	Sets whether Kerberos and GSSAPI user names should be treated as case-insensitive.
krb_server_keyfile	Cluster	Reload	EPAS service account	Sets the location of the Kerberos server key file.
lc_collate	Database	Preset	n/a	Shows the collation order locale.
lc_ctype	Database	Preset	n/a	Shows the character classification and case conversion locale.
lc_messages	Session	Immediate	Superuser	Sets the language in which messages are displayed.
lc_monetary	Session	Immediate	User	Sets the locale for formatting monetary amounts.
lc_numeric	Session	Immediate	User	Sets the locale for formatting numbers.
lc_time	Session	Immediate	User	Sets the locale for formatting date and time values.
listen_addresses	Cluster	Restart	EPAS service account	Sets the host name or IP address(es) to listen to.
local_preload_libraries	Cluster/ Session	Reload/ Immediate	EPAS service account/ User	Lists shared libraries to preload into each backend. (Can also be set with PGOPTIONS at session start.)
lock_timeout	Session	Immediate	User	Sets the maximum time allowed that a statement may wait for a lock.
lo_compat_privileges	Session	Immediate	Superuser	Enables backward compatibility mode for privilege checks on large objects.
log_autovacuum_min_duration	Cluster	Reload	EPAS service account	Sets the minimum execution time above which autovacuum actions will be logged.
log_checkpoints	Cluster	Reload	EPAS service account	Logs each checkpoint.
log_connections	Cluster/ Session	Reload/ Immediate	EPAS service account/ User	Logs each successful connection. (Can also be set with PGOPTIONS at session start.)
log_destination	Cluster	Reload	EPAS service account	Sets the destination for server log output.
log_directory	Cluster	Reload	EPAS service account	Sets the destination directory for log files.
log_disconnections	Cluster/ Session	Reload/ Immediate	EPAS service account/ User	Logs end of a session, including duration. (Can also be set with PGOPTIONS at session start.)
log_duration	Session	Immediate	Superuser	Logs the duration of each completed SQL statement.
log_error_verbosity	Session	Immediate	Superuser	Sets the verbosity of logged messages.
log_executor_stats	Session	Immediate	Superuser	Writes executor performance statistics to the server log.
log_file_mode	Cluster	Reload	EPAS service account	Sets the file permissions for log files.
log_filename	Cluster	Reload	EPAS service account	Sets the file name pattern for log files.
log_hostname	Cluster	Reload	EPAS service account	Logs the host name in the connection logs.
log_line_prefix	Cluster	Reload	EPAS service account	Controls information prefixed to each log line.
log_lock_waits	Session	Immediate	Superuser	Logs long lock waits.
log_min_duration_statement	Session	Immediate	Superuser	Sets the minimum execution time above which statements will be logged.
log_min_error_statement	Session	Immediate	Superuser	Causes all statements generating error at or above this level to be logged.
log_min_messages	Session	Immediate	Superuser	Sets the message levels that are logged.
log_parser_stats	Session	Immediate	Superuser	Writes parser performance statistics to the server log.
log_planner_stats	Session	Immediate	Superuser	Writes planner performance statistics to the server log.
log_rotation_age	Cluster	Reload	EPAS service account	Automatic log file rotation will occur after N minutes.
log_rotation_size	Cluster	Reload	EPAS service account	Automatic log file rotation will occur after N kilobytes.
log_statement	Session	Immediate	Superuser	Sets the type of statements logged.
log_statement_stats	Session	Immediate	Superuser	Writes cumulative performance statistics to the server log.
log_temp_files	Session	Immediate	Superuser	Log the use of temporary files larger than this number of kilobytes.
log_timezone	Cluster	Reload	EPAS service account	Sets the time zone to use in log messages.
log_truncate_on_rotation	Cluster	Reload	EPAS service account	Truncate existing log files of same name during log rotation.
logging_collector	Cluster	Restart	EPAS service account	Start a subprocess to capture stderr output and/or csvlogs into log files.
maintenance_work_mem	Session	Immediate	User	Sets the maximum memory to be used for maintenance operations.
max_connections	Cluster	Restart	EPAS service account	Sets the maximum number of concurrent connections.
max_files_per_process	Cluster	Restart	EPAS service account	Sets the maximum number of simultaneously open files for each server process.
max_function_args	Cluster	Preset	n/a	Shows the maximum number of function arguments.
max_identifier_length	Cluster	Preset	n/a	Shows the maximum identifier length.
max_index_keys	Cluster	Preset	n/a	Shows the maximum number of index keys.
max_locks_per_transaction	Cluster	Restart	EPAS service account	Sets the maximum number of locks per transaction.
max_pred_locks_per_transaction	Cluster	Restart	EPAS service account	Sets the maximum number of predicate locks per transaction.
max_prepared_transactions	Cluster	Restart	EPAS service account	Sets the maximum number of simultaneously prepared transactions.
max_replication_slots	Cluster	Restart	EPAS service account	Sets the maximum number of simultaneously defined replication slots.
max_stack_depth	Session	Immediate	Superuser	Sets the maximum stack depth, in kilobytes.
max_standby_archive_delay	Cluster	Reload	EPAS service account	Sets the maximum delay before canceling queries when a hot standby server is processing archived WAL data.
max_standby_streaming_delay	Cluster	Reload	EPAS service account	Sets the maximum delay before canceling queries when a hot standby server is processing streamed WAL data.
max_wal_senders	Cluster	Restart	EPAS service account	Sets the maximum number of simultaneously running WAL sender processes.
max_wal_size	Cluster	Reload	EPAS service account	Sets the maximum size to which the WAL will grow between automatic WAL checkpoints. The default is 1GB.
max_worker_processes	Cluster	Restart	EPAS service account	Maximum number of concurrent worker processes.
min_wal_size	Cluster	Reload	EPAS service account	Sets the threshold at which WAL logs will be recycled rather than removed. The default is 80 MB.
nls_length_semantics	Session	Immediate	Superuser	Sets the semantics to use for char, varchar, varchar2 and long columns.	X
odbc_lib_path	Cluster	Restart	EPAS service account	Sets the path for ODBC library.	X
optimizer_mode	Session	Immediate	User	Default optimizer mode.	X
oracle_home	Cluster	Restart	EPAS service account	Sets the path for the Oracle home directory.	X
password_encryption	Session	Immediate	User	Encrypt passwords.
pg_prewarm.autoprewarm	Cluster	Restart	EPAS service account	Enables the autoprewarm background worker.	X
pg_prewarm.autoprewarm_interval	Cluster	Reload	EPAS service account	Sets the minimum number of seconds after which autoprewarm dumps shared buffers.	X
port	Cluster	Restart	EPAS service account	Sets the TCP port on which the server listens.
post_auth_delay	Cluster/ Session	Reload/ Immediate	EPAS service account/ User	Waits N seconds on connection startup after authentication. (Can also be set with PGOPTIONS at session start.)
pre_auth_delay	Cluster	Reload	EPAS service account	Waits N seconds on connection startup before authentication.
qreplace_function	Session	Immediate	Superuser	The function to be used by Query Replace feature. Note: For internal use only.	X
query_rewrite_enabled	Session	Immediate	User	Child table scans will be skipped if their constraints guarantee that no rows match the query.	X
query_rewrite_integrity	Session	Immediate	Superuser	Sets the degree to which query rewriting must be enforced.	X
quote_all_identifiers	Session	Immediate	User	When generating SQL fragments, quote all identifiers.
random_page_cost	Session	Immediate	User	Sets the planner's estimate of the cost of a nonsequentially fetched disk page.
restart_after_crash	Cluster	Reload	EPAS service account	Reinitialize server after backend crash.
search_path	Session	Immediate	User	Sets the schema search order for names that are not schema-qualified.
segment_size	Cluster	Preset	n/a	Shows the number of pages per disk file.
seq_page_cost	Session	Immediate	User	Sets the planner's estimate of the cost of a sequentially fetched disk page.
server_encoding	Database	Preset	n/a	Sets the server (database) character set encoding.
server_version	Cluster	Preset	n/a	Shows the server version.
server_version_num	Cluster	Preset	n/a	Shows the server version as an integer.
session_preload_libraries	Session	Immediate but only at connection start	Superuser	Lists shared libraries to preload into each backend.
session_replication_role	Session	Immediate	Superuser	Sets the session's behavior for triggers and rewrite rules.
shared_buffers	Cluster	Restart	EPAS service account	Sets the number of shared memory buffers used by the server.
shared_preload_libraries	Cluster	Restart	EPAS service account	Lists shared libraries to preload into server.
sql_inheritance	Session	Immediate	User	Causes subtables to be included by default in various commands.
ssl	Cluster	Restart	EPAS service account	Enables SSL connections.
ssl_ca_file	Cluster	Restart	EPAS service account	Location of the SSL certificate authority file.
ssl_cert_file	Cluster	Restart	EPAS service account	Location of the SSL server certificate file.
ssl_ciphers	Cluster	Restart	EPAS service account	Sets the list of allowed SSL ciphers.
ssl_crl_file	Cluster	Restart	EPAS service account	Location of the SSL certificate revocation list file.
ssl_ecdh_curve	Cluster	Restart	EPAS service account	Sets the curve to use for ECDH.
ssl_key_file	Cluster	Restart	EPAS service account	Location of the SSL server private key file.
ssl_prefer_server_ciphers	Cluster	Restart	EPAS service account	Give priority to server ciphersuite order.
ssl_renegotiation_limit	Session	Immediate	User	Set the amount of traffic to send and receive before renegotiating the encryption keys.
standard_conforming_strings	Session	Immediate	User	Causes '...' strings to treat backslashes literally.
statement_timeout	Session	Immediate	User	Sets the maximum allowed duration of any statement.
stats_temp_directory	Cluster	Reload	EPAS service account	Writes temporary statistics files to the specified directory.
superuser_reserved_connections	Cluster	Restart	EPAS service account	Sets the number of connection slots reserved for superusers.
synchronize_seqscans	Session	Immediate	User	Enable synchronized sequential scans.
synchronous_commit	Session	Immediate	User	Sets immediate fsync at commit.
synchronous_standby_names	Cluster	Reload	EPAS service account	List of names of potential synchronous standbys.
syslog_facility	Cluster	Reload	EPAS service account	Sets the syslog "facility" to be used when syslog enabled.
syslog_ident	Cluster	Reload	EPAS service account	Sets the program name used to identify PostgreSQL messages in syslog.
tcp_keepalives_count	Session	Immediate	User	Maximum number of TCP keepalive retransmits.
tcp_keepalives_idle	Session	Immediate	User	Time between issuing TCP keepalives.
tcp_keepalives_interval	Session	Immediate	User	Time between TCP keepalive retransmits.
temp_buffers	Session	Immediate	User	Sets the maximum number of temporary buffers used by each session.
temp_file_limit	Session	Immediate	Superuser	Limits the total size of all temporary files used by each session.
temp_tablespaces	Session	Immediate	User	Sets the tablespace(s) to use for temporary tables and sort files.
timed_statistics	Session	Immediate	User	Enables the recording of timed statistics.	X
timezone	Session	Immediate	User	Sets the time zone for displaying and interpreting time stamps.
timezone_abbreviations	Session	Immediate	User	Selects a file of time zone abbreviations.
trace_hints	Session	Immediate	User	Emit debug info about hints being honored.	X
trace_notify	Session	Immediate	User	Generates debugging output for LISTEN and NOTIFY.
trace_recovery_messages	Cluster	Reload	EPAS service account	Enables logging of recovery-related debugging information.
trace_sort	Session	Immediate	User	Emit information about resource usage in sorting.
track_activities	Session	Immediate	Superuser	Collects information about executing commands.
track_activity_query_size	Cluster	Restart	EPAS service account	Sets the size reserved for pg_stat_activity.current_query, in bytes.
track_counts	Session	Immediate	Superuser	Collects statistics on database activity.
track_functions	Session	Immediate	Superuser	Collects function-level statistics on database activity.
track_io_timing	Session	Immediate	Superuser	Collects timing statistics for database I/O activity.
transaction_deferrable	Session	Immediate	User	Whether to defer a read-only serializable transaction until it can be executed with no possible serialization failures.
transaction_isolation	Session	Immediate	User	Sets the current transaction's isolation level.
transaction_read_only	Session	Immediate	User	Sets the current transaction's read-only status.
transform_null_equals	Session	Immediate	User	Treats "expr=NULL" as "expr IS NULL".
unix_socket_directories	Cluster	Restart	EPAS service account	Sets the directory where the Unix-domain socket will be created.
unix_socket_group	Cluster	Restart	EPAS service account	Sets the owning group of the Unix-domain socket.
unix_socket_permissions	Cluster	Restart	EPAS service account	Sets the access permissions of the Unix-domain socket.
update_process_title	Session	Immediate	Superuser	Updates the process title to show the active SQL command.
utl_encode.uudecode_redwood	Session	Immediate	User	Allows decoding of Oracle-created uuencoded data.	X
utl_file.umask	Session	Immediate	User	Umask used for files created through the UTL_FILE package.	X
vacuum_cost_delay	Session	Immediate	User	Vacuum cost delay in milliseconds.
vacuum_cost_limit	Session	Immediate	User	Vacuum cost amount available before napping.
vacuum_cost_page_dirty	Session	Immediate	User	Vacuum cost for a page dirtied by vacuum.
vacuum_cost_page_hit	Session	Immediate	User	Vacuum cost for a page found in the buffer cache.
vacuum_cost_page_miss	Session	Immediate	User	Vacuum cost for a page not found in the buffer cache.
vacuum_defer_cleanup_age	Cluster	Reload	EPAS service account	Number of transactions by which VACUUM and HOT cleanup should be deferred, if any.
vacuum_freeze_min_age	Session	Immediate	User	Minimum age at which VACUUM should freeze a table row.
vacuum_freeze_table_age	Session	Immediate	User	Age at which VACUUM should scan whole table to freeze tuples.
vacuum_multixact_freeze_min_age	Session	Immediate	User	Minimum age at which VACUUM should freeze a MultiXactId in a table row.
vacuum_multixact_freeze_table_age	Session	Immediate	User	Multixact age at which VACUUM should scan whole table to freeze tuples.
wal_block_size	Cluster	Preset	n/a	Shows the block size in the write ahead log.
wal_buffers	Cluster	Restart	EPAS service account	Sets the number of disk-page buffers in shared memory for WAL.
wal_keep_segments	Cluster	Reload	EPAS service account	Sets the number of WAL files held for standby servers.
wal_level	Cluster	Restart	EPAS service account	Set the level of information written to the WAL.
wal_log_hints	Cluster	Restart	EPAS service account	Writes full pages to WAL when first modified after a checkpoint, even for non-critical modifications.
wal_receiver_status_interval	Cluster	Reload	EPAS service account	Sets the maximum interval between WAL receiver status reports to the primary.
wal_receiver_timeout	Cluster	Reload	EPAS service account	Sets the maximum wait time to receive data from the primary.
wal_segment_size	Cluster	Preset	n/a	Shows the number of pages per write ahead log segment.
wal_sender_timeout	Cluster	Reload	EPAS service account	Sets the maximum time to wait for WAL replication.
wal_sync_method	Cluster	Reload	EPAS service account	Selects the method used for forcing WAL updates to disk.
wal_writer_delay	Cluster	Reload	EPAS service account	WAL writer sleep time between WAL flushes.
work_mem	Session	Immediate	User	Sets the maximum memory to be used for query workspaces.
xloginsert_locks	Cluster	Restart	EPAS service account	Sets the number of locks used for concurrent xlog insertions.
xmlbinary	Session	Immediate	User	Sets how binary values are to be encoded in XML.
Xmloption	Session	Immediate	User	Sets whether XML data in implicit parsing and serialization operations is to be considered as documents or content fragments.
zero_damaged_pages	Session	Immediate	Superuser	Continues processing past damaged page headers.