PSQL Tips & Tricks - DanysoftPSQL Tips & Tricks 13 Skip the first 10 rows, return the next 5: SELECT * FROM Person LIMIT 5 OFFSET 10; SELECT * FROM Person LIMIT 10,5; Skip the first

Confidential © 2016 Actian Corporation1 Confidential © 2016 Actian Corporation

PSQL Tips & TricksFor Maintenance and Support

Linda AndersonManager, PSQL Sustaining Engineering

Actian User ConferenceOctober 2016

Confidential © 2016 Actian Corporation2

What’s New?

PSQL Tips & Tricks

What’s Old?

What’s Secret?

PS

QL

13

What’s Next?


What’s New?

■ AuditMaster 12

■ DataExchange 12

■ Automatic Defragmentation

■ New SQL Syntax

PSQL Tips & Tricks


What’s New – AuditMaster 12 & Audit for PSQL-J

■ Support for auditing files with long owner names

■ New AM database format uses long owner name + encryption (no SQL Access)

■ Integration with PSQL security models secured via DEFAULTDB

PSQL Tips & Tricks


What’s New – AuditMaster 12

■ AMViewer login is different depending on DEFAULTDB security

PSQL Tips & Tricks

Unsecured or Mixed Mode:

Database Mode:


What’s New – AuditMaster 12

■ Did you know AM supports “Undo Operation(s)”?

PSQL Tips & Tricks


What’s New – Data Exchange 12

■ Compatible with PSQL v12

■ Rebranded for Actian

■ Reformatted and updated documentation

PSQL Tips & Tricks


What’s New – Automatic Defragmentation

■ One hour after the setting is turned on, the engine begins File Discovery for defragmentation criteria:

• > 10MB

• > 15% Fragmented

• > 15% Unused Space

• > 5% Out of Order

■ Looks at files opened since the engine started.

PSQL Tips & Tricks


What’s New – SQL Syntax

■ TOP clause supports dynamic parameter

■ CREATE/ALTER TABLE supports non-existing relative paths

PSQL Tips & Tricks

CREATE PROCEDURE TopTest (:howmany integer) RETURNS (LastName varchar(25)) AS

BEGIN

SELECT TOP :howmany last_name FROM student, person WHERE student.id = person.id;

END;

CALL TopTest (6);

In an application: SELECT TOP ? * FROM Person

create table t1 using '..\newpath\t1.mkd' (id identity, name char(20));

create table t2 using '.\subfolder\t2.mkd' (id identity, name char(20));


What’s New – SQL Syntax

■ CREATE INDEX … USING #

■ DROP TABLE IF EXISTS

PSQL Tips & Tricks

CREATE INDEX “Citizen-x” USING 3 ON Person (citizenship);

CREATE INDEX “abc” USING 2 IN DICTIONARY ON t1 (name);

DROP TABLE IF EXISTS t1;

DROP TABLE IF EXISTS t2 IN DICTIONARY;


What’s Next – PSQL 13

■ Database Schema Export/Import

■ New SQL Syntax

PSQL Tips & Tricks

PS

QL

13



■ Database Schema Export/Import (aka DumpDB)

■ Primary Use Cases:

• Migrate a database from v1 to v2 metadata

• Export schema for review/maintenance/migration

• Duplicate a database with a set of empty data files

■ Demo Time!

PSQL Tips & Tricks

PS

QL

13



■ New SQL Syntax: LIMIT with OFFSET

• Similar to MySQL & Sybase

• Comparable to ROW_NUMBER() <SQLServer>, rownum <Oracle>

• Provides ability to paginate

• Cannot be used in the same sub-statement as TOP

■ New SQL Syntax: ORDER BY in Expression Subquery

PSQL Tips & Tricks

PS

QL

13

Skip the first 10 rows, return the next 5:

SELECT * FROM Person LIMIT 5 OFFSET 10;

SELECT * FROM Person LIMIT 10,5;

Skip the first 10 rows, return all remaining rows:

SELECT * FROM Person LIMIT ALL OFFSET 10

select D.Name, (select top 1 Last_Name, Cumulative_GPA from Student S, Person P

where S.ID = P.ID and S.Major = D.Name order by Cumulative_GPA DESC)

from Dept D;


What’s Old?

■ Function Executor History

■ Query Plan Viewer

PSQL Tips & Tricks


What’s Old – Function Executor History

PSQL Tips & Tricks


What’s Old – Function Executor History

■ History Shows all the operations executed

■ Can Execute one or more operations, with a repeat count

■ Supports Export & Import of one or more operations

PSQL Tips & Tricks


What’s Old - Query Plan Viewer

■ Captures the PSQL’s execution plan associated with queries as they are executed.

■ Applies to the current SQL session

■ For ODBC, can use registry settings:

PSQL Tips & Tricks

SET QRYPLANOUTPUT = ‘c:\ProgramData\Actian\PSQL\logs\queries.qpf’;

SET QRYPLANOUTPUT = NULL;

SET QRYPLAN = ON;

SET QRYPLAN = OFF;


What’s Old - Query Plan Viewer

PSQL Tips & Tricks

set qryplanoutput = 'c:\ProgramData\Actian\PSQL\demodata\demo.qpf';

select (select class.name from class where enrolls.class_id=class.id ) as classname,

person.*,enrolls.* from person,enrolls

where person.id=enrolls.student_id and last_name like 'c%'

order by last_name,classname;


What’s Secret?

■ Undocumented SQL Syntax

■ Undocumented Registry Settings

PSQL Tips & Tricks


What’s Secret – Undocumented SQL Syntax

■ Create legacy data types in legacy files

■ Switch database context

PSQL Tips & Tricks

SET LEGACYTYPESALLOWED = ON;

SET TRUENULLCREATE = OFF;

CREATE TABLE oldtable (id identity, name lstring(10), misc note(8000));

USE MyDB;

SELECT * FROM T1;

USE DEMODATA;

SELECT * FROM Billing;


What’s Secret – Undocumented Registry Settings

■ Extended Operations Reject Count Override

• A large reject count could cause other threads in the engine to be blocked waiting for the Extended operation to finish.

• HKEY_LOCAL_MACHINE\SOFTWARE\Pervasive Software\MicroKernel Server Engine\Version 12\Settings

• Name: Reject Count

• Type: DWORD

• Values: 1-4095 (default is 4095)

PSQL Tips & Tricks



■ Optimize on Btrieve Null Keys

• SQL engine can use an index that corresponds to a Btrieve key using the Null attribute.

• HKEY_LOCAL_MACHINE\SOFTWARE\Pervasive Software\SQL Relational Engine

• Name: UseBtrieveExcludeNullKey

• Type: String

• Values: NO | YES

PSQL Tips & Tricks



■ Data Exchange: Make DX Operations Atomic

• Regulates if the updates/insert/deletes to the user tables and to the corresponding PDC tables are done as atomic operations (in a transaction).

• Use if DX introduces unexpected errors such as 84, 85, 78, etc.

• HKEY_LOCAL_MACHINE\SOFTWARE\Pervasive Software\Pervasive Replication\

• Name: MakeDXOpsAtomic

• Type: String

• Values: YES | NO

PSQL Tips & Tricks



■ SQL Engine: Maximum Number of Tables Cached per Databases

• SQL engine caches metadata information for each database, which can consume a large amount of memory

• In an environment with many active databases, with large numbers of tables, you may want to limit how much metadata is cached

• HKEY_LOCAL_MACHINE\SOFTWARE\Pervasive Software\SQL Relational Engine

• Name: MaxCachedTables

• Type: String

• Values: 1-4095; Default=1500

PSQL Tips & Tricks


Q & A


Thank You!


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PSQL Tips & Tricks - DanysoftPSQL Tips & Tricks 13 Skip the first 10 rows, return the next 5: SELECT * FROM Person LIMIT 5 OFFSET 10; SELECT * FROM Person LIMIT 10,5; Skip the first