SQL/MP Reference Manual

HP NonStop SQL/MP Reference Manual—523352-013
L-13
Limits
A header is 32 bytes for key-sequenced tables and 22 bytes for relative and entry-
sequenced tables. In addition, there are two bytes overhead for each row in a
block.
For Format 2 key-sequenced tables, a file header is of 56 bytes.

Statement length
The maximum length of an SQL/MP statement is 32,767 characters, including
blanks.

Subquery nesting
Queries can be nested a maximum of 16 levels, including the outermost query.

SYSKEY value
The value range allowed for a SYSKEY (system-defined primary key) is 0 through
4,294,963,199 for the 4-byte primary key used in a table with relative or
entry-sequenced file organization; the range is 0 through 2**63-1 for the 8-byte
primary key (actually, a timestamp) used in a table with key-sequenced file
organization.

Tables per query
The maximum possible number of tables in a database, if enough memory is
available, is 32,767. Only 16 of these tables can be referred to in any given query.

Temporary file size
The size of a temporary file is limited to the space available on the disk on which
the file resides. Temporary files provide space for sort operations required for some
queries, for creating indexes, for splitting partitions, and for loading tables.

Transactions per table
The limit on the number of TMF transactions or update transactions that can be
active on a given SQL table is the same as the limit on the number of transactions
that can be active in your NonStop system. That number is configurable and
depends on the TRANSPERCPU attribute of the BEGINTRANS object of TMF. For
more information, see the description of the ALTER BEGINTRANS command in
the TMF Reference Manual.

User-defined primary key length
The sum of the column lengths for the columns of the key cannot exceed 255
bytes.

User process sort
No more than 32,767 rows can be sorted.

View definition