Upgrading and Migrating an IQ database from older ... - Sybase

ASE 15 Upgrade Checklist for Upgrading from ASE 12.x Sybase ASE 15
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Keep this increased utilization in mind when planning disk space, and when observing I/O rates in
tempdb. The amount of increased tempdb usage will vary, depending on the optimization goals you
use, the features you use, and your specific workload mix.
STEP 4.6.4: SEMANTIC PARTITIONING AND SIZING THE NUMBER OF OPEN PARTITIONS
Table partitioning is another new feature of ASE 15. Although semantic data partitioning is an optional
license feature, its introduction affects resource consumption even when it is not enabled. That is, each
table and index consists of at least one partition in ASE 15. Consequently, the value of the configuration
parameter “number of open partitions” must be set high enough to avoid unnecessary performance
overhead in the reuse of this resource.
As a starting point, Sybase recommends using sp_countmetadata to estimate the required setting for
this parameter and then use sp_monitorconfig to monitor usage. Keep in mind that temp tables are
not included in the results of sp_countmetadata.
STEP 4.6.5: STATEMENT CACHE AND LITERAL AUTO-PARAMETERIZATION
Advantages of Enabling Statement Cache and Literal Auto Parameterization
Due to the increased complexity of query optimization in ASE 15, the query optimizer will typically
use significantly more resources (compilation time and procedure cache) than in prior versions.
Therefore, if you are running many identical, or similar SQL queries (queries that differ only in their
search argument), we strongly recommend enabling both statement cache and the new literal autoparameterization
feature (introduced in ASE 15.0.1). These settings will improve overall performance
by reducing the time and resources required by the query optimizer.
Statement Cache: When statement cache is enabled, the first execution of a query results in the
caching of its query plan. When the query runs again, it reuses the cache plan rather than recompile
it again, thus improving performance by saving time and resources.
Literal Auto-Parameterization: With literal auto-parameterization enabled, caching is extended to
almost-identical queries that differ only in a constant value, and are likely to end up with the same
plan. Therefore, literal auto-parameterization can greatly improve the effectiveness of your
statement cache. We recommended that you enable and test this feature if your application uses
many almost-identical SQL queries that are not part of stored procedures and are not run in executeimmediate.
Enabling Statement Cache
The statement cache is enabled sever-wide with the configuration parameter:
1> sp_configure "statement cache size"
2> go
Note: The statement cache can be disabled at the session level using the set statement cache off.
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ASE 15 Upgrade Checklist for ASE 12.X v3.0 Page 73 of 97 Last Update: May, 2012