Wweatheredin0xweathered.hashnode.dev·Oct 16, 2021 · 3 min readsql | dev | automatic partitions for the lazy kind - automatic list partitioningnah, using sample schema is way easier actually, lets go to HR lets say i want to make a stripped down table identical to the EMPLOYEES table, paritioned, by DEPARTMENT_ID column. so if i am using the HR.EMPLOYEES table, SELECT COUNT(DISTINCT DEPAR...00
Wweatheredin0xweathered.hashnode.dev·Oct 16, 2021 · 2 min readsql | how to avoid multiple identical subqueries in the SELECT clausecontinuing from sql | how NOT to avoid multiple identical subqueries in the SELECT clause these won't work if your db is older than 12c. if it is lower, i guess the how NOT to is the how to, not an expert don't quote me on that. and no i don't want ...00
Wweatheredin0xweathered.hashnode.dev·Oct 15, 2021 · 1 min readsql | how NOT to avoid multiple identical subqueries in the SELECT clauserunning 12c or higher? how to inline subqueries in SELECT clauses, or simply scalar subqueries, as you can guess by the name, is used to return a single value. but what if, i am having to query a specific table, writing identical subqueries to fet...00
Wweatheredin0xweathered.hashnode.dev·Oct 15, 2021 · 1 min readdba | ORA-01000: maximum open cursors exceedednot the best place for explanations here, the below query shows the number of open cursors present in a session. if the number reaches the db parameterOPEN_CURSORS, ORA-01000 is thrown. OPEN_CURSORS := number of cursors each session can have open, pe...00
Wweatheredin0xweathered.hashnode.dev·Oct 15, 2021 · 1 min readsql tuning | calculating logical reads made by a queryone day a dba reported high resource usage by a query, but it was 'well-optimized' and the runtime was as expected, then what was wrong? logical read was high. to calculate logical reads made by a query: DECLARE READS NUMBER; OUTPUT NUMBER; ...00
