Dynamic software updating ksplice

28-Nov-2019 15:07

This is how to prepare the LOAD table before the exchange: Q2 will have fresh statistics and a synopsis as soon as the exchange completes. Statistics on Q2 will be gathered again after the exchange (when statistics are gathered on SALES) unless you have created appropriate histograms and extended statistics on LOAD before the exchange.The list_script in Git Hub displays extended statistics and histograms for a particular table if you want to take a look at what you have.

I'm also going to assume that the statistics on SALES are up-to-date prior to the partition exchange load.It’s common to see it used in decision support systems and large operational data stores.Make sure you’ve taken a look at Part 1, or you are at least familiar with the concept of incremental statistics so that you know what a synopsis is in the context of a partitioned table.There is nevertheless a scenario where you might want to gather statistics on LOAD prior to the exchange.For example, if it’s likely that Q2 will be queried before statistics have been gathered on SALES then you might want to be sure that statistics are available on Q2 as soon as the exchange completes.

I'm also going to assume that the statistics on SALES are up-to-date prior to the partition exchange load.It’s common to see it used in decision support systems and large operational data stores.Make sure you’ve taken a look at Part 1, or you are at least familiar with the concept of incremental statistics so that you know what a synopsis is in the context of a partitioned table.There is nevertheless a scenario where you might want to gather statistics on LOAD prior to the exchange.For example, if it’s likely that Q2 will be queried before statistics have been gathered on SALES then you might want to be sure that statistics are available on Q2 as soon as the exchange completes.In the example above, the global-level statistics for SALES must be refreshed to reflect the data incorporated into the table when LOAD is exchanged with Q2.