|
| 1 | +createtabletmptab (pkintegerprimary key, skinteger); |
| 2 | + |
| 3 | +-- insert ebnough records to make psotgresql optimizer use indexes |
| 4 | +insert into tmptabvalues (generate_series(1,10000), generate_series(1,10000)); |
| 5 | + |
| 6 | +vacuum analyze; |
| 7 | + |
| 8 | +-- create normal index |
| 9 | +createindexidxon tmptab(sk); |
| 10 | + |
| 11 | +-- just normal index search |
| 12 | +select*from tmptabwhere sk=100; |
| 13 | + |
| 14 | +-- make index partial |
| 15 | +alterindex idxwhere pk<1000; |
| 16 | + |
| 17 | +-- select using exact partial index range |
| 18 | +select*from tmptabwhere sk=100and pk<1000; |
| 19 | +explainselect*from tmptabwhere sk=100and pk<1000; |
| 20 | + |
| 21 | +-- select using subset of partial index range |
| 22 | +select*from tmptabwhere sk=100and pk<200; |
| 23 | +explainselect*from tmptabwhere sk=100and pk<200; |
| 24 | + |
| 25 | +-- select outside partial index range |
| 26 | +select*from tmptabwhere sk=100and pk>1000; |
| 27 | +explainselect*from tmptabwhere sk=100and pk>1000; |
| 28 | + |
| 29 | +-- select without partial index range |
| 30 | +select*from tmptabwhere sk=100; |
| 31 | +explainselect*from tmptabwhere sk=100; |
| 32 | + |
| 33 | +-- extend partial index range |
| 34 | +alterindex idxwhere pk<10000; |
| 35 | + |
| 36 | +-- select using exact partial index range |
| 37 | +select*from tmptabwhere sk=1000and pk<10000; |
| 38 | +explainselect*from tmptabwhere sk=1000and pk<10000; |
| 39 | + |
| 40 | +-- calculating aggregate within exact partial index range |
| 41 | +selectcount(*)from tmptabwhere sk<1000and pk<10000; |
| 42 | +explainselectcount(*)from tmptabwhere sk<1000and pk<10000; |
| 43 | + |
| 44 | +-- reducing partial idex predicate |
| 45 | +alterindex idxwhere pk<9000; |
| 46 | + |
| 47 | +-- select using new exact partial index range and key value belonging to old range |
| 48 | +select*from tmptabwhere sk=9000and pk<9000; |
| 49 | +explainselect*from tmptabwhere sk=9000and pk<9000; |
| 50 | + |
| 51 | +-- select using exact partial index range |
| 52 | +select*from tmptabwhere sk=900and pk<9000; |
| 53 | +explainselect*from tmptabwhere sk=900and pk<9000; |
| 54 | + |
| 55 | +droptable tmptab; |