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KC Informix Users Group 10 Cheetah 2 Features. Presented By: Sanjit Chakraborty / Jeff Laube Date: Jan 22, 2009. Agenda. Enhanced Configuration Options During Installation Automatic Statistics Updating Control External Directives for a Session

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kc informix users group 10 cheetah 2 features

KC Informix Users Group 10 Cheetah 2 Features

Presented By: Sanjit Chakraborty / Jeff Laube

Date: Jan 22, 2009

  • Enhanced Configuration Options During Installation
  • Automatic Statistics Updating
  • Control External Directives for a Session
  • Automatic Statistics & Distributions with Create Index
  • Enhanced Startup script customization
  • Visual Explain
  • Secure Socket Layer (SSL)
  • Savepoints
enhanced configuration options during installation
Enhanced Configuration Options During Installation

Instance Configuration Wizard

  • Automatically creates and custom onconfig file for future use
  • The onconfig file generates during create demonstration database server with custom setup
  • GUI and Console installation wizard both supports
  • Windows limitation –
    • Only available with a custom setup in GUI mode
    • Not available with silent installation
  • Parameters value decides depending on hardware and database system needs
  • Configuration file generated with Standard setting for any error encountered during using wizard
input for configuration file
Input for Configuration File
  • Installation Directory
  • Database Server Name
  • Server Number
  • Rootpath
  • Rootsize
  • No. of central processing units (CPUs)
  • Memory: System RAM dedicated to the IDS server (in MB)
  • No. of online transaction clients
  • No. of decision support clients
updated configuration parameters
Updated Configuration Parameters
files generated
Files Generated
  • Customized Onconfig file
    • /etc
  • Onconfig file
    • onconfig.
  • Updated onconfig parameters will be added at bottom of the file
  • Environment Setup Files
    • /demo/server
      • profile_settings (ksh)
      • Profile_settings.csh
enhanced configuration options during installation instance configuration wizard
Enhanced Configuration Options During InstallationInstance Configuration Wizard

UNIX install (either Typical or Custom)

Do you want to create an IDS demonstration database server instance?

[X] 1 - Yes

[ ] 2 - No

Demonstration Database Instance Configuration

[ ] 1 - Use my own configuration file.

[ ] 2 - Use the default configuration file.

[X] 3 - Customize the default configuration file to suit your needs and hardware.

Specify your server configuration parameters (Server Number should be in the range of 0 to 255).

Server Name [demo_on] ids1150

Server Number [0] 50

ROOTPATH [/usr2/products/11.50.UC2/demo/server/online_root] /chunks/1152/chunk1

ROOTSIZE (MB) [760] 204800

Press 1 for Next, 2 for Previous, 3 to Cancel or 4 to Redisplay [1]

Configuration Setup

Modify any values if you want to customize database server configuration settings.

Processors to use [1] 1

Memory to use (MB) [512] 128

Online Transaction Clients (applications that frequently update databases with multiuser input) [1] 1000

Decision Support Clients (applications for querying databases to gather reporting information) [1] 25

enhanced configuration options during installation instance configuration wizard1
Enhanced Configuration Options During InstallationInstance Configuration Wizard

Installation log after configuration parameters set:

Installing IBM Informix Dynamic Server Version 11.50. Please wait...

Creating demonstration database server instance ...

Creating demonstration database server instance ... - Creating demonstration database server onconfig file at


Creating demonstration database server instance ... - Demonstration database server instance initialized successfully .

Please read the information below.

The IBM Informix Dynamic Server demonstration database server has been created.

Check the log file to determine if it was successfully initialized: /usr2/products/11.50.UC2/demo/server/online.log.

(Note: the above log is the verbose output to screen, it is not logged to a physical file)

why auto update statistics aus
Why Auto Update Statistics (AUS)?
  • Users must update statistics and distributions manually to help optimizer make correct decisions to run query efficiently
    • Many of us do not realize this and encounter poor performance
  • When to run Update Statistics?
  • What statistics and distributions need to be updated?
    • Not easy to understand
    • Change periodically
    • Differ for each system
  • AUS provides ability to automate the maintenance of optimizer statistics
aus implementation
AUS Implementation
  • A set of procedures which will be invoked by the database scheduler to automate update statistics
    • Installed as part of the server
    • Users can write SQL statements to manipulate the AUS configuration
  • Open Admin Tool (OAT) graphical interface allows easier control of the different AUS policies
    • Open source download available from iiug.org and IBM websites
    • Display AUS information in easy to read format
    • Simple point and click interface
aus implementation database tasks
AUS Implementation - Database Tasks
  • Tasks in ph_task table
  • Auto Update Statistics Evaluation
    • Analyzes all the tables in all logged databases
    • Locates tables which require new or updated optimizer statistics
    • Builds the update statistics commands
    • Inserts the commands into the table aus_cmd_list
  • Auto Update Statistics Refresh
    • Executes the update statistics commands from aus_cmd_list table in a priority order within a specified time
    • After the command completes, it is moved to the aus_cmd_comp table
configuration parameters ph threshold table
Configuration Parameters – PH_THRESHOLD Table

Use OAT AUS configuration page or update sysadmin:ph_threshold to

modify these parameters

scheduling information
Scheduling Information
  • Since AUS is a resource intensive operation, a specific run window can be defined. The run window definition includes start time, the end time and the days of the week to run the job.
  • Can be configured from the Open Admin tool.
  • Implemented by setting the start and end times of the AUS refresh (Auto Update Statistics Refresh) task in ph_task table in sysadmin.
  • Default runtime window is 1:00 AM – 5:00 AM daily.


indexes and statistics distributions
Indexes and Statistics/Distributions
  • Without statistics or distributions

the index will not be considered by the optimizer

  • Common Mistake
    • Create an index and see no improvement in select performance
  • We need to run UPDATE STATISTICS

LOW at a minimum for newly created

indexes to be considered for query access plans.

Why can’t this be done automatically when new indexes are created?

create index distributions statistics
Create Index Distributions & Statistics
  • Implicit or explicit CREATE INDEX automatically creates statistics & distribution for the leading column of an index

SET EXPLAIN Output for CREATE INDEX statement:

CREATE INDEX idx1 on tab1(col1_int)

Index: idx1 on informix.tab1


Column Distribution for: informix.tab1.col1_int

Mode: HIGH

Number of Bins: 207 Bin size: 4800.0

Sort data: 0.9 MB

Completed building distribution in: 0 minutes 1 seconds

  • Enabled always -- cannot turn off
limitations to create index distributions
Limitations to Create Index Distributions
  • Index distributions are NOT created when --
    • If the lead of the index is a UDT (builtin or non-builtin)
    • Index is a functional index
    • Index is a VII index
    • Number of rows in table is < 2


external directives previous references
External Directives (Previous references)

Query performance problems and you cannot change it because

  • You don’t own the application or a 3rd party application
  • You don't have the source code access or the developer is unavailable
  • The application is heavily used and can't be switched off without schedule a downtime
  • Update statistics or change OPTCOMPIND

doesn't affect

external directives previous references1
External Directives (Previous references)
  • External optimizer directives are useful when it is not feasible rewrite a query for a short-term solution to a problem
  • Enabling external directives

Environment Variable: IFX_EXTDIRECTIVES

Configuration parameter: EXT_DIRECTIVES

  • Directives saved in sysdirectives catalog
example external directive
Example: External Directive
  • Schema for table items

create table items


item_num smallint,

order_num integer,

stock_num smallint not null ,

manu_code char(3) not null ,

quantity smallint,

total_price money(8,2)


create index items_idx1 on items (item_num, manu_code);

  • Query runs from an application which used the items_idx1 index path

SELECT item_num, manu_code

FROM items

WHERE manu_code = "ANZ"

example external directive cont
Example: External Directive (cont.)
  • Some reason query is running slow because of sequential scan instead follow the index path
  • Update statistics is not helpful
  • Only way query can ran faster, using INDEX directive

SELECT {+INDEX (items item_idx1)}

item_num, manu_code

FROM items

WHERE manu_code = "ANZ"

  • Without changing the application code force optimizer to chose the index path
  • Solution is use external directive
example external directive cont1
Example: External Directive (cont.)
  • Save and Active the query as external directive

SAVE EXTERNAL DIRECTIVES --+INDEX(items item_idx1) ACTIVE FORSELECT item_num, manu_code

FROM items

WHERE manu_code = "ANZ"

  • If external directive enabled, query should follow the index path

Environment Variable: IFX_EXTDIRECTIVES

Configuration parameter: EXT_DIRECTIVES

session level external directives
Session Level External Directives


  • New EXTDIRECTIVES session environment option of the SET ENVIRONMENT statement
  • Overwrites the EXT_DIRECTIVES configuration parameter
  • Controls whether external directives are enabled, disabled or have default behavior during a session
  • Default behavior specified in the EXT_DIRECTIVES ONCONFIG parameter and client-side environment variable IFX_EXTDIRECTIVES
control external directives for a session
Control External Directives for a Session
  • Syntax




  • Example

* Disable external directives within a session



new oninit option w
New oninit option: -w
  • Use to customize startup scripts and automate startup for the oninitutility.
  • The -w option forces the server to wait until it successfully initializes before returning a shell prompt.
  • The -w option provides a return code so that you can check if the IDS started without incident

return 0 when success

return 1 when initialization fails or configurable

timeout achieved

  • In case of failure online.log updated appropriately
oninit w delay
oninit -w
  • Configurable timeout period during server initializes

oninit –w

  • If fails return 1 with a message in online.log:

Warning: wait time expired

  • Default timeout: 600 sec
  • Return code 1- Not necessary server crash or failure
  • In a high-availability environment, you can only use the oninit -w command on primary servers; it is not valid on secondary servers
  • Returns success when sysmaster, sysutils, sysuser and sysadmin are successfully created


visual explain
Visual Explain
  • A new user defined function (C-UDR) EXPLAIN_SQL was implemented in IDS11.50.
  • The new UDR EXPLAIN_SQL can be used to obtain a query explain output in XML format.
  • IBM Data Studio can interpret the XML formatted explain file and show the query plan graphically to the user.
Visual Explain
  • EXPLAIN_SQL UDR is mainly implemented to allow common tooling such as the new IBM Data Studio to be able to get XML explain output through the function and show users the graphical query plans.
  • If user wants to obtain the XML explain output and use their own graphic tool to see the query plan, the UDR should be ran by JDBC or JCC program.
Visual Explain
  • Example of JDBC program running EXPLAIN_SQL

CallableStatement cstmt2 =

conn.prepareCall("{call informix.explain_sql(?, ?, ?, ?, ?, ?, ?)}");

/* set up the parameters */

cstmt2.registerOutParameter( 1, Types.INTEGER );

cstmt2.registerOutParameter( 2, Types.INTEGER );


cstmt2.setNull( 5, Types.BLOB ); // Filter

cstmt2.registerOutParameter( 6, Types.BLOB ); // XML_OUTPUT

cstmt2.registerOutParameter( 7, Types.BLOB ); // XML_MESSAGE

file = new File("./xmlins");

fin = new FileInputStream(file);

byte[] buffer = new byte[8000];

IfxLobDescriptor loDesc = new IfxLobDescriptor(conn);

IfxLocator loPtr = new IfxLocator();

IfxSmartBlob smb = new IfxSmartBlob(conn);

int loFd = smb.IfxLoCreate(loDesc, smb.LO_RDWR, loPtr);

n = fin.read(buffer);

if (n > 0) n = smb.IfxLoWrite(loFd, buffer);


Blob blb = new IfxBblob(loPtr);

cstmt2.setBlob(4, blb); // set the blob column

Visual Explain
  • Example of JDBC program running EXPLAIN_SQL … continued

ResultSet rs = cstmt2.executeQuery();

int outmajver = cstmt2.getInt(1);

int outminver = cstmt2.getInt(2);

/* read the xml explain output if there is any */

while (rs.next())


byte[] buf = new byte[80000];

b = (IfxBblob) rs.getBlob(1);

if (b != null


IfxLocator loptr = b.getLocator();

IfxSmartBlob smbl = new IfxSmartBlob(conn);

int lofd = smbl.IfxLoOpen(loptr, smbl.LO_RDONLY);

outfile = new File("./out.xml");

fout = new FileOutputStream(outfile);

int size = smbl.IfxLoRead(lofd, fout, 80000);





Visual Explain
  • Example of JDBC program running EXPLAIN_SQL … continued

/* get blob out parameters */

outmsg_b = (IfxBblob)cstmt2.getBlob(7);

if (outmsg_b == null)

System.out.println("outmsg_b is null");



IfxLocator xml_msg_loptr = outmsg_b.getLocator();

IfxSmartBlob xml_msg_smbl = new IfxSmartBlob(conn);

int msg_out_lofd = xml_msg_smbl.IfxLoOpen(xml_msg_loptr,


msg_out_outfile = new File("./xml_msg.xml");

msg_out_fout = new FileOutputStream(msg_out_outfile);

int xml_msg_size = xml_msg_smbl.IfxLoRead(msg_out_lofd,

msg_out_fout, 80000);




Visual Explain
  • Sample XML explain output

select * from chartab where c1 = 2 ;





Visual Explain
  • Sample visual explain in Data studio
bigint bigserial overview
  • New ANSI standard SQL data types BIGINT and BIGSERIAL were introduced in IDS.
  • Aims to provide a better performance alternative to INT8 and SERIAL8 data types. However, IDS will continue its support of INT8 and SERIAL8 data types in existing customer applications.
bigint bigserial description
  • INT8 and SERIAL8 data types which are internally implemented as a 10-byte structure, ifx_int8_t. INT8 and SERIAL8 take up to 10 byte of storage in IDS.
  • This feature will implement BIGINT and BIGSERIAL data types using native 8-byte integers. It will take 8-byte to store these data types.
  • Like INT8, BIGINT will store numbers range from 9,223,372,036,854,775,807 to 9,223,372,036,854,775,807 [(2^63-1) to 2^63-1].
  • The number –9,223,372,036,854,775,808 is a reserved for a NULL value and cannot be used.
bigint bigserial description1
  • Like SERIAL8, BIGSERIAL will store numbers range from 1 to 9,223,372,036,854,775,807 [or 1 to 2^63-1].
  • Compare to INT8, BIGINT requires less storage space and more important, should offer better performance in general because all arithmetic operations will be done using the native 8-byte integer instead of dealing with the 10-byte ifx_int8_t structure.
  • BIGINT and BIGSERIAL will be reserved keywords.
  • A table can have only one SERIAL column, and either one SERIAL8 column or one BIGSERIAL column.
bigint bigserial description2
  • BIGINT and BIGSERIAL uses native 8-byte data type of the OS. On 32-bit platforms it is ‘long long’. Under certain compiler options the ‘long long’ is not supported. During compilations of customer application if they detect error they can remove the Compiler option that causes not define ‘long long’. The alternative to this compile with –DNOBIGINT, by doing this customer may not be able to use this feature fully in their applications.
  • The new SQL data types will be classified as Exact Numeric Types under Built-in Data Types and will be applicable to all DDL/DML statements wherever built-in data types are currently used.
bigint bigserial description3
  • The BIGINT and BIGSERIAL SQL data types is supported in the following products
    • IDS and its Utilities
    • ESQL/C
    • ODBC
    • JDBC
    • Common Clients and derivatives
bigint bigserial example
  • INSERT INTO T1 VALUES (0, 1234567);


A <= 1000000000 IN DBSPACE2,

A > 1000000000 AND A <= 29990000000 IN DBSPACE3,

A > 29990000000 AND A <= 999999999999999 IN DBSPACE1;

secure socket layer
Secure Socket Layer
  • Communication protocol that provides privacy and integrity for data communication over the network
  • Uses encryption to provide end-to-end secure connection
  • At present, IDS supports encrypted communication only with SQLI clients (using Encryption Communication Support Module)
  • With SSL, encrypted communication will be possible with DRDA clients too
digital certificates certificate authority ca and keystores
Digital Certificates, Certificate Authority (CA) and Keystores
  • Digital Certificates are electronic ID cards issued by trusted parties know as Certificate Authority (e.g. VeriSign)
  • SSL feature in IDS uses digital certificates to exchange keys for encryption and server authentication
  • Digital certificates are stored in key database (also known as keystore)
  • IBM’s Global Security Kit bundled with IDS server and client provides an iKeyman utility that can be used to create keystores and manage digital certificates
digital certificates cont
Digital Certificates cont…
  • Both client and server must have keystore for housing digital certificates
  • Server side keystore will store digital certificate issued (or signed) by Certificate Authority such as VeriSign
  • Client side keystore will store digital certificate of Certificate Authority (also called root certificate) that issued the server digital certificate
setting up ssl sqlhosts
Setting up SSL - SQLHOSTS
  • New communication protocol
    • drsocssl protocol for supporting SSL communication with DRDA clients
    • onsocssl/olsocssl protocol for supporting SSL communication with SQLI clients. SSL will also be supported with server to server communication (ISTAR, HDR, ER, SDS/RSS)
  • Example
    • lenexa_on onsoctcp pinchy lenexa_serv
    • menlo_on onsocssl pinchy menlo_serv
    • portland_on drsocssl pinchy portland_serv
setting up ssl onconfig
Setting up SSL - ONCONFIG
  • New parameters
    • SSL_KEYSTORE_LABEL – Specifies label of server digital certificate in keystore. If not configured, the server will use the default label in keystore for SSL communication

e.g. SSL_KEYSTORE_LABEL ids_label

  • Changes to existing parameters
    • NETTYPE – Describes connection parameters such as number of poll threads, max connections and class of virtual process for poll threads for connection protocols

NETTYPE protocol, poll threads, connections, VP class

Specify the protocol as iiippp

where: iii=[ipc|ipc|soc|tli]


e.g. NETTYPE socssl, 3, 50, NET

setting up ssl onconfig1
Setting up SSL - ONCONFIG
  • All SSL encryption/decryption operations are performed on encrypt VP. Encrypt VPs can be configured via VPCLASS parameter

e.g. VPCLASS encrypt, num=5

  • SSL and non-SSL connection protocols can be configured for a single instance using server aliases

e.g. DBSERVERNAME menlo_on

DBSERVERALIASES lenexa_on, portland_on

wheremenlo_on is onsocssl, lenexa_on is onsoctcp and

portland_on is drsocssl connection protocol

setting up ssl keystores and digital certificates
Setting up SSL – Keystores and Digital certificates
  • IBM’s Global Security Kit (GSKit) will be installed as part of IDS and CSDK installations
  • GSKit contains iKeyman utility that can be used to create keystores and manage digital certificates needed for SSL communication
  • More information on iKeyman is available at:


setting up ssl keystores and digital certificates1
Setting up SSL – Keystores and Digital certificates
  • The keystore for server is password protected. Password is stored encrypted in stash file (also created by iKeyman utility)
  • One keystore per server instance. It stores server’s digital certificate and root CA certificates of other servers its connecting to (as in ISTAR, HDR, ER, SDS/RSS)
  • Location and name of server keystore and its password stash file is predefined:



The ownership/permissions of above files must be informix:informix/600

is value of DBSERVERNAME onconfig parameter

setting up ssl keystores and digital certificates2
Setting up SSL – Keystores and Digital certificates
  • Password is optional for client keystore.
  • Client keystore stores root CA certificates of all servers the client is connecting to. SQLI and DRDA clients can share same keystore
  • Location and name of client keystore and its password stash file can be configured via new configuration file:
    • $INFORMIXDIR/etc/conssl.cfg

New client configuration parameters:

    • SSL_KEYSTORE_FILE – Specifies fully qualified filename of client keystore
    • SSL_KEYSTORE_STH – Specifies fully qualified filename of client stash file

If conssl.cfg does not exist or if any of above parameters are not configured, the keystore and stash file will default to:

$INFORMIXDIR/etc/client.kdb and $INFORMIXDIR/etc/client.sth

setting up ssl keystores and digital certificates3
Setting up SSL – Keystores and Digital certificates
  • Prerequisites for iKeyman utility
    • IBM JDK/JRE 1.3.1, 1.4.1 or higher with JCE PKS Security packages
  • Environment for iKeyman utility
    • export JAVA_HOME=
    • export PATH=$JAVA_HOME/jre/bin:$PATH
    • export CLASSPATH=/classes/cfwk.zip:/classes/gsk7cls.jar:$JAVA_HOME/jre/lib/ext/ibmpkcs11.jar
setting up ssl keystores and digital certificates4
Setting up SSL – Keystores and Digital certificates

Sample commands for creating keystore and self-signed test

certificates* using iKeyman command line utility:

  • Server Keystore
    • gsk7cmd -keydb -create -db menlo_on.kdb -pw snoopy -type cms -stash
    • gsk7cmd -cert -create -db menlo_on.kdb -pw snoopy -label ids_label -dn "CN=menlo.ibm.com,O=ibm,C=US" -size 1024 -default_cert yes
    • gsk7cmd -cert -extract -db menlo_on.kdb -format ascii -label ids_label -pw snoopy -target ids_label.cert

where DBSERVERNAME is menlo_on


  • Client Keystore
    • gsk7cmd -keydb -create -db client.kdb -pw snoopy -type cms -stash
    • gsk7cmd -cert -add -db client.kdb -pw snoopy -label ids_label -file ids_label.cert -format ascii

*In production systems, digital certificates will be requested from Certificate Authority.

Refer to iKeyman User Guide for more information on this.

recap of ssl setup
Recap of SSL setup
  • sqlhosts for client and server
    • onsocssl/drsocssl
  • onconfig for server
    • NETTYPE for socssl
    • VPCLASS for encrypt VP
  • conssl.cfg for client
  • keystores and digital certificates for client and server
  • Initialize server and all communication between client and server or between servers on onsocssl/drsocssl port will be encrypted using SSL protocol
savepoint description
Savepoint Description
  • New SQL statements and options offer a mechanism to undo portions of an SQL transaction
  • A user can arbitrarily mark points within one SQL transaction, called a savepoint
  • If an error occurs during execution, it can rollback the database changes made between the time the savepoint was started and the time the savepoint rollback request is issued.
savepoint new sql
Savepoint: new SQL
  • Establish a savepoint





  • Destroy a savepoint



savepoint enhanced sql
Savepoint: Enhanced SQL
  • Rollback to a savepoint



savepoint example
Savepoint Example

SAVEPOINT order_two;


UPDATE goods_one SET count = count – order_quantity;

UPDATE goods_two SET count = count – order_quantity;

# if any of the above two statements fail, rollback to savepoint order_two


order_quantity -=20;

goto order;

#if both update statements succeed, erase the savepoint order_two


savepoints and jdbc
Savepoints and JDBC
  • JDBC will support this feature implementing these standard methods defined in java.sql.Connection interface.
  • Savepoint setSavepoint() throws SQLException;
  • Savepoint setSavepoint(String name) throws SQLException;
  • Void rollback(Savepoint savepoint) throws SQLException
  • Void releaseSavepoint(Savepoint savepoint) throws SQLException
  • New ONCONFIG parameter:

LIMITNUMSESSIONS max#sessions, print_warning

max#sessions = 0 to 2097152. The default is 0.

print_warning = 0 (off) or 1 (on). The default is 0.

  • Defines the max number of sessions that you want connected to IDS.
  • Warning messages will be reported to the online.log as the max value is approached if print_warning is on.
limitnumsessions example
  • ONCONFIG setting:


  • Because print_warning is on, an online.log message reports that the max number of sessions, 100, is being approached as the number of user sessions closes in on this limit
  • If user session 101 attempts to connect to the server, the error -25571 is reported to client and a message in the online.log reports that the maximum number of sessions has been reached and no new sessions can connect until the current number of connections falls below this limit
limitnumsessions additional information
LIMITNUMSESSIONS Additional Information
  • LIMITNUMSESSIONS is not intended to provide a means for enforcing user license agreements.
  • LIMITNUMSESSIONS will not affect informix or DBSA users.