SQL/MX 2.x Installation and Management Guide (H06.10+, J06.03+)

Enhancing SQL/MX Database Performance

HP NonStop SQL/MX Installation and Management Guide—544536-007

15-20

Avoiding Automatic Recompilations

Automatic recompilation can become a significant performance concern. In most

cases, you should attempt to run valid programs at all times to ensure the best

possible performance.

Automatic recompilation makes it possible for application programs to continue to

perform when invalidating events occur or when access paths are unavailable. The

time required to perform the recompilation, however, can noticeably add to the initial

response time of the application program that contains the SQL statements.

Matching Block Split Operation to Table Usage

In a table with key-sequenced organization, when an INSERT operation causes a data

block to overflow, the DP2 process must make room for the new row by splitting the

block in the middle and transferring some of its contents to a newly allocated block.

Because NonStop SQL/MX does not support the SEQUENTIAL BLOCKSPLIT option

for the CONTROL TABLE statement, you cannot split the block at the insertion point

when rows are being inserted in sequence.