Physical Limitations

Limitations exist on the size of objects and the number of objects in Sybase IQ databases. In most cases, computer memory and disk drive are more limiting factors.

For limitations that apply to only one platform, see the platform-specific documentation.

Sybase IQ Database Object Size and Number Limitations

Item

Limitation

Catalog file size

Maximum is 1TB for all platforms. Windows systems with NTFS support the 1TB maximum.

Database name size

250 bytes

Database size

Maximum database size approximates the number of files times the file size on a particular platform, depending on the maximum disk configuration.

Refer to your operating system documentation for kernel parameters that affect the maximum number of files.

Dbfile size

Determined by the operating system file size

Dbspace size

Raw device: Maximum size is 4T.

File system device: Maximum size is 4TB

Operating system file: Maximum size supported by the operating system

Sybase does not recommend creating dbspaces on NAS (Network Attached Storage) devices

Field size

255 bytes for BINARY, 32,767 bytes for VARBINARY

32,767 for CHAR, VARCHAR

Up to 512 TB for 128 KB pages or 1 PB for 512 KB pages for LONG BINARY, LONG VARCHAR

IQ page size

Must be between 64KB and 512KB

Maximum key size

255 bytes for single-column index. 5300 bytes for multicolumn index

Maximum length of string literal

32KB

Maximum length of SQL statement

The maximum length of SQL statements is limited to the amount of memory available for the IQ catalog, and to the size of the catalog stack

If your SQL statements are long, increase the catalog stack size using -gss, and increase catalog memory cache size using -c or a combination of -ch and -cl

When printing the SQL statement in error messages, the text is limited to the IQ catalog page size. To print long commands, you can start the server with an increased -gp setting, although in general Sybase recommends that you use the default of -gp 4096.

Maximum length of variable-length FILLER column

512 bytes

Maximum number of dbfiles

The total number of files that can be opened depends on the number of unique file descriptors that an operating system can support

Maximum number of users (connected and concurrent)

1000 on 64-bit platforms AIX, HP, Linux, and Sun Solaris

200 on 64-bit platforms on Windows

Maximum size of temp extract file

Set by TEMP_EXTRACT_SIZEn option. Platform limits are:

AIX & HP-UX: 0 – 64GB

Sun Solaris: 0 – 512GB

Windows: 0 – 128GB

Linux: 0 – 512GB

Number of columns per table

Sybase IQ supports up to 45,000 columns in a table. You may see performance degradation if you have more than 10,000 columns in a table. The limit on the number of columns per table that allow NULLs is approximately 8*(database-page-size - 30).

Number of events per database

2^31 – 1 = 2 147 483 647

Number of files per database

Operating system limit that user can adjust; for example, using NOFILE. Typically, 2047 files per database

Number of indexes

2^32 (~4,000,000) per table

Number of rows per table

Limited by table size, upper limit 2^48 -1

Number of stored procedures per database

2^32 – 1 = 4 294 967 295

Number of tables or views in a single FROM clause

16 – 64, depending on the query, with join optimizer turned on

Number of tables or views referenced per query

512

Number of tables per database

4,293,918,719

Number of tables per join index (number of tables that can be joined in one query block)

31

Number of tables referenced per transaction

No limit.

Number of UNION branches per query

512. If each branch has multiple tables in the FROM clause, the limit on tables per query reduces the number of UNION branches allowed.

Number of values in an IN list

250,000

Row size

Sybase recommends a limit of half the page size

Table size

Limited by database size

Related reference
String Functions