Restrictions

Consider information about restrictions to avoid unexpected results from your system.

This information applies to servers and databases of this version of Sybase IQ that have been upgraded from any earlier version of Sybase IQ, unless specified otherwise.

Sybase Central Plug-in Compatibility [CR #667451]

Due to security fixes in IQ 15.3, the Sybase IQ 15.3 plug-in for Sybase Central™ and Sybase Central Agents are not compatible with versions of Sybase IQ earlier than 15.2 ESD #3. You can use the 15.3 plug-in only with Sybase IQ servers that are 15.2 ESD #3 or later, including 15.3; you cannot use the 15.3 plug-in to connect to 12.x servers or servers earlier than 15.2 ESD #3.See New Features Summary.

Database Name Length Restriction [CR #365281]

The dbbackup utility truncates the database name to 70 characters and creates a target file with a truncated name. Sybase IQ uses dbbackup when synchronizing secondary servers. Due to dbbackup restrictions, database names must be less than 70 characters long.

Dbspace Management and File Placement

When you allocate file system files for dbspaces (System, IQ Main, or IQ Temporary), do not place the files on a file system that is shared over a local area network. Doing so can lead to poor I/O performance and other problems, including overloading the local area network. Do not place IQ dbspace files on network drives or Network File System (NFS) file systems.

To avoid conflicts, Sybase recommends that dbspace management be performed by a single database administrator on a single connection.

Dbspace Naming in RESTORE Command [CR #561366]

If the dbspace name contains a file extension such as .iq, .iqtmp, or .iqloc, you must enclose the dbspace name in double quotation marks when specifying the name in a RESTORE command RENAME clause. For example:

RENAME local1 TO '/work/local1_res.iqloc.iqloc' 
DBSPACENAME "local1_res.iqloc"

RENAME "test_prod2.iq" TO '/test/test_prod7.iq'

Unexpected Query Results

In a few unusual circumstances, differences in semantics between SQL Anywhere and Sybase IQ may produce unexpected query results. These circumstances are:

A query is issued from inside a user-defined function
A SELECT statement has no FROM clause
A FROM clause contains some tables that were created IN SYSTEM and others that were not created IN SYSTEM

In these circumstances, subtle differences between the semantics of SQL Anywhere and Sybase IQ may be exposed. These differences include:

Sybase IQ treats the CHAR and VARCHAR data types as distinct and different; SQL Anywhere treats CHAR data as if it were VARCHAR.
When the RAND function is passed an argument, the behavior is deterministic in Sybase IQ and nondeterministic in SQL Anywhere.

Interactive SQL Restrictions

Sybase recommends that you use dbisql, rather than dbisqlc or iqisql, unless instructed to do otherwise, for specific tasks. dbisqlc is supported, but does not contain all the features of dbisql.

Do not use the Import option on the dbisql Data menu (or Command | Options | Input Format in dbisqlc). This option is not supported for use with IQ databases. Use the LOAD TABLE statement or the INSERT statement to load data into IQ tables.
If you run dbisql (Interactive SQL) with the -q (quiet mode) option, and the data extraction commands (primarily setting the option TEMP_EXTRACT_NAME1 to an output file) are in a command file, you must first set and make permanent the dbisql option “Show multiple result sets.” If you do not set this option, the output file is not created.

To set the option “Show multiple result sets,” click Tools | Options in the dbisql window, choose "Sybase IQ," and select the "Results" tab. Under "Results Processing" and "For statements that return multiple result sets," select "Show all result sets."
There is no online help for dbisql and dbisqlc. [CR #560925]
The query plan in the dbisql Plan tab is a SQL Anywhere style query plan. For a Sybase IQ query plan, refer to the IQ .iqmsg file.
If you set the terminal type on UNIX and Linux systems to “dumb” or “unknown” and then start dbisqlc, Sybase IQ returns an error. For example:
```
% setenv TERM dumb
% dbisqlc
```
error at line 1 Unable to initialize screen routines
To avoid problems, run dbisql (Interactive SQL) instead, or use an xterm window to run dbisqlc on UNIX and Linux systems. For example, to start an xterm window with a scroll bar, enter:
```
% xterm -sb
```