Major Description
Steps to reproduce are as follows:
1. Create a table
create table tbl (col1 varchar primary key, col2 varchar);
2. Create a view on the table
create view vw (col3 varchar) as select * from tbl;
3. Create a index on the table
create index idx ON tbl (col2);
After those, when issuing a explain query like the following, it seems like the query doesn't use the index, although the index should be used:
0: jdbc:phoenix:> explain select /*+ INDEX(vw idx) */ * from vw where col2 = 'aaa'; +---------------------------------------------------------------+ | PLAN | +---------------------------------------------------------------+ | CLIENT 1-CHUNK PARALLEL 1-WAY ROUND ROBIN FULL SCAN OVER TBL | | SERVER FILTER BY COL2 = 'aaa' | +---------------------------------------------------------------+
However, after restarting sqlline, the explain output is changed, and the index is used.
0: jdbc:phoenix:> explain select /*+ INDEX(vw idx) */ * from vw where col2 = 'aaa'; +--------------------------------------------------------------------------------+ | PLAN | +--------------------------------------------------------------------------------+ | CLIENT 1-CHUNK PARALLEL 1-WAY ROUND ROBIN FULL SCAN OVER TBL | | SKIP-SCAN-JOIN TABLE 0 | | CLIENT 1-CHUNK PARALLEL 1-WAY ROUND ROBIN RANGE SCAN OVER IDX ['aaa'] | | SERVER FILTER BY FIRST KEY ONLY | | DYNAMIC SERVER FILTER BY "VW.COL1" IN ($3.$5) | +--------------------------------------------------------------------------------+
I think when creating an index on a table, meta data cache of views related to the table isn't updated, so the index isn't used for that query. However after restarting sqlline, the meta data cache is refreshed, so the index is used.
When creating an index on a table, we should update meta data cache of views related to the table.