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How to enable disabled (by default) performance features in SAP Sybase ASE 15.x

Starting in Adaptive SAP SybaseServer version 15.0.3 ESD #2, performance related optimizer changes are not enabled by default. Users will need to test the enhancements using specific set options. In addition, functionality has been added to switch on/off previous optimizer changes and features. This white paper discusses how and when to enable the changes.

Because the optimizer changes are not enabled by default, applications already running efficiently are not affected by, nor will the necessarily benefit from, these changes when upgrading to the latest ESD.

In 15.0.3 ESD #3 and above, we introduced support for global Optlevels. Enabling these changes increases query performance for many applications, though Sybase recommends additional performance testing.

In 15.5 ESD 3 and above, we introduced 15.5 global Optlevels that match the 15.5 ESD level. Prior to ESD 3, 15.0.3 ESD versions were mapped to 15.5.

Example:
set plan optlevel ase_current

Table 1-1: Available optlevels

 

 

Value Defined
ase_current enable all optimizer changes up through the current ESD
ase_default disable all optimizer changes since 1503 esd #1
ase1503esd2 enable all optimizer changes up through 15.0.3 ESD #2
ase1503esd3 enable all optimizer changes up through 15.0.3 ESD #3
ase1503esd4 enable all optimizer changes up through 15.0.3 ESD #4
ase155esd3 enable all optimizer changes up through 15.5 ESD #3
ase155esd4 enable all optimizer changes up through 15.5 ESD #4
ase_current on ASE 15.7 GA enable all optimizer changes up through 15.5 ESD #4
ase155esd5 enable all optimizer changes up through 15.5 ESD #5
ase157esd1 enable all optimizer changes up through 15.7 ESD #1
ase_current on ASE 15.7 ESD#2 enable all optimizer changes up through 15.7 ESD #1

Read the complete White Paper (Technote 1080354) at SAP

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Comments

  1. Heriberto Martinez Bastida says:

    Hey Jason! I didn’t know you had this type of page in internet, it’s awesome, thanks for sharing 🙂

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