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

More documents

Recommendations

Info

ASE 15 Upgrade Checklist for Upgrading from ASE 12.x Sybase ASE 15 _________________________________________________________________________________________________ 3. allrows_dss: This is the best goal for Decision Support (DSS) applications, medium-to-high complexity applications that use NLJ, SMJ, HJ sort/hash based grouping, bushy tree plans, and parallelism. To allow for fine-tuning of query performance, optimizer goals can be set at the server, session or query level. Goals set at the session level override the server level; goals set at query level override the session level. 2. Testing Goals In ASE 15, the allrows_mix goal was chosen as the server-level default because it can accommodate the widest range of queries. However, this goal may not be the best for all, or even some, of your queries. Therefore, the purpose of testing ASE’s optimizer goals is two-fold: 1) To identify the best serverlevel optimizer goal; 2) To identify any queries or applications that require a different session level or query level goal. 3. One Goal May Not Work for All In complex processing environments, no single optimizer goal will be best for ALL queries. This is especially the case where there is a skewed workload mix. That is, where the applications mix is comprised mostly of one type of processing with a small number of another type. For example, mostly OLTP with just a few DSS reports; or, mostly DSS reports/batch processing with a small mix of OLTP. In these cases, it is best to set the server-level optimizer goal to the one goal that provides the best performance for the greatest number of queries. Then, override this server-level setting at either the session level, or query level, as needed to meet the performance requirements of a particular application or individual query. 4. Testing Strategies To determine which optimizer goals are best for your server, test all of the optimizer goals and compare the results to your pre-upgrade performance baseline: In general, it is best to begin your performance testing using the default goal of allrows_mixed. Depending on your performance results and requirements, test each of the other two goals using all or just some of your queries: o o o You may find that all of your queries perform as well or better than they did on your preupgrade server when using the default goal. In this case, you may not need to continue testing. However, you may find that some of your queries do not perform as well as they did on your pre-upgraded server. In this case, repeat your tests using one of the other optimizer goals for those slow performing queries. The recommended approach is to test ALL of your queries using all three optimizer goals. This way, you will identify the optimizer goal that works best for each query, as well as which goal works best for the majority of queries. ___________________________________________________________________________________________________________ ASE 15 Upgrade Checklist for ASE 12.X v3.0 Page 83 of 97 Last Update: May, 2012
ASE 15 Upgrade Checklist for Upgrading from ASE 12.x Sybase ASE 15 _________________________________________________________________________________________________ o Use the goal that performs the best for the most number of queries as your server-level setting. Than, override this goal at the session or query level as needed for individual queries or applications. 5. Implementation Examples To set the optimizer goal at the Server Level, do the following: > sp_configure "optimization goal", 0, "allrows_dss" To set the optimizer goal at the Session Level: > set plan optgoal allrows_mix To set the optimizer goal at the Query Level: > select * from blah plan "(use optgoal allrows_oltp)" The individual optimization algorithms used under various optgoals can also be turned on and off at the session level, for example: o o o set nl_join ON/OFF set parallel_query ON/ OFF set merge_join ON/OFF 6. Additional Testing Considerations If you are still finding that one or more queries, stored procedures or other compiled objects have worsened in performance, we recommend you consider the following: o o o o o o First, review Steps 2.7, 4.3, 4.4 and 4.5 regarding table and index-level statistics and ensure that the tables and indices involved all have up-to-date statistics. Second, if you have not already done so, re-run the query or procedure under each of the different optimization goals (in Step 4.9) to see if one generates a better plan than the others. Third, verify that your new server level configuration settings (in steps 4.6 and 4.7) are satisfactory. Fourth, for troubleshooting slow performing queries, it is very useful to compare the postupgrade query plans to you pre-upgrade query plans. This comparison can be used in performing the advanced tuning techniques listed below. Fifth, consider the advanced tuning techniques discussed in the steps below for: • Optimizer Level Settings • Abstract Plans • The New QPTune Tool Lastly, if all the above fails, then consider the optimizer compatibility mode discussed below. ___________________________________________________________________________________________________________ ASE 15 Upgrade Checklist for ASE 12.X v3.0 Page 84 of 97 Last Update: May, 2012
Page 1 and 2:
ASE 15 Upgrade Checklist For Upgrad
Page 3 and 4:
ASE 15 Upgrade Checklist for Upgrad
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Page 33 and 34: ASE 15 Upgrade Checklist for Upgrad
Page 83: ASE 15 Upgrade Checklist for Upgrad
Page 97: ASE 15 Upgrade Checklist for Upgrad
show all

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

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?