NonStop SQL/MP Reference Manual

NonStop SQL/MP Reference Manual—142115
L-10
Limits
If you see one of these errors, you can increase PFS size using the BINDER SET
PFS integer command, as follows:
1>RENAME SQLCAT,ZZSQLCAT
2>BIND
@ADD * FROM ZZSQLCAT
@SET PFS 256
@SELECT LIST (* OFF)
@BUILD SQLCAT !
@EXIT
3>FUP LICENSE SQLCAT
Alternately, for programs executed using TACL, you can specify PFS size in the
TACL RUN command.
Increase PFS size selectively, only as the need arises. Keep the original copy of any
program that requires a larger PFS setting. If you increase the PFS setting for
SQLCAT or SQLUTIL, you must license the new copy. If you increase the PFS
setting for SQLCI2, you must SQL compile the new copy.
•
Partitions per index or key-sequenced table, extended partition array
Typically, if the primary key of the index or key-sequenced table is between 10 and
50 bytes, the maximum number of partitions allowed can be from 230 (for the
smaller key size) down to 110 (for the larger key size).
If the key of an index is between 10 and 50 bytes, the maximum number of index
partitions is typically between 180 (for keys of 10 bytes) and 60 (for keys of 50
bytes). In some situations, the maximum might be as few as 38.
Factors that affect the number of allowed partitions are the data types of the columns
of the primary key and the number of catalogs used to describe the partitions. Also,
the description of the partitioned table or index must fit in a file label.
•
Partitions per relative or entry-sequenced table
This type of limit on partitions for a table is affected by the same restrictions that
apply to key-sequenced tables with standard partition arrays. Additional restrictions
also apply because of dependencies on the number and size of extents and on
primary key values.
The following information can help you estimate the maximum number of partitions
allowed for relative or entry-sequenced tables:
°
When you partition a table, NonStop SQL/MP evenly distributes all possible
rows (identified by primary key value) into the partitions in both primary and
secondary extents using the MAXEXTENTS attribute value to determine the
number of extents and the EXTENTS attribute to determine extent sizes.
(Relative files have SYSKEY values that begin at 0 and increment by 1. Entry-
sequenced files have SYSKEY values based on the block number.)