Wouldn't disk_read and memory_read be better naming? - Denis
On Wed, Jan 16, 2019 at 7:38 AM Юрий <[email protected]> wrote: > Denis, > > Physical reads is load page from storage to memory. > Logical reads is read page which already in memory. > > We gather IO statistics on CACHE_GROUP level due to Ignite use one page to > keep all caches related to one cache group. Unfortunately gathering on > table level will be expensive due to the reason. That's way name of view > contains words cache and groups. > > ср, 16 янв. 2019 г. в 17:52, Denis Magda <[email protected]>: > > > Yury, > > > > How do we differentiate between logical and physical reads? > > > > Also, it looks counter-intuitive when "CACHE" is used in the name of the > > views for SQL table related statistics. It's still hard to explain the > user > > the relations between caches and tables. Hopefully, this will be fixed in > > 3.0 with renaming but as for the statistics can we use anything neutral > for > > the view names? > > > > - > > Denis > > > > > > On Tue, Jan 15, 2019 at 5:57 AM Юрий <[email protected]> > wrote: > > > > > Hi Igniters! > > > > > > As part of IEP-27 > > > < > > > > > > https://cwiki.apache.org/confluence/display/IGNITE/IEP-27%3A+Page+IO+statistics > > > > > > > we > > > already gathering IO statistics and expose it through JMX. > > > > > > User who use only SQL should have access to the statistics also. So > > let's > > > discuss about how such SQL view should looks. > > > > > > My proposal it is two SQL views: > > > 1) STATIO_CACHE_GRP > > > > > > cache_grp_name - Name of cache group > > > physical_read - Number of physical read of pages > > > logical_read - Number of logical read of pages > > > > > > > > > The view can be filtered by name, like SELECT * from > > > IGNITE.STATIO_CACHE_GRP where cache_grp_name='cache1' > > > 2) STATIO_IDX > > > > > > cache_grp_name - Name of cache group > > > > > > idx_name - Name of index > > > physical_read - Common number of physical reads of pages > > for > > > the index > > > logical_read - Common number of logical reads of pages > > for > > > the index > > > > > > leaf_logical_read - Number of logical reads of index leaf > pages > > > > > > leaf_physical_read - Number of physical reads of index leaf pages > > > > > > inner_logical_read - Number of logical reads of index inner > pages > > > > > > inner_physical_read - Number of physical reads of index leaf pages > > > > > > > > > The view can be filtered by cache group name or by index name, > like > > > SELECT * from IGNITE.STATIO_IDX where idx_name='cache1_name_idx' > > > > > > We also have time of start gathering statistics, but I'm not sure that > it > > > should be exposed here. > > > > > > > > > WDYT about proposed format for the SQL views? > > > > > > > > > > > > > > > > > > > > > -- > > > Живи с улыбкой! :D > > > > > > > > -- > Живи с улыбкой! :D >
