WebJan 26, 2005 · Well, I noted that (see above). But there is another thing that PK constraints enforce while unique indexes do not: NOT NULL. Even though I cannot imagine of what help would a B*Tree index be for finding NULLs, an index takes relatively long time to build, so you should have the option of not having to rebuild it when you later enable the constraint … WebIn Oracle script I have this code: CREATE UNIQUE INDEX "PK_PORTALROLES" ON "PORTAL_ROLE" ("ROLE_NAME"); ALTER TABLE "PORTAL_ROLE" ADD CONSTRAINT "PK_PORTALROLES" PRIMARY KEY ("ROLE_NAME") USING INDEX ENABLE; Question (1) From the code above what is the USING INDEX command in the ALTER TABLE line doing?
how to disable or mark an index unusable and enable the index
WebAug 10, 2024 · While Oracle Database can combine B-trees (via a "bitmap conversion from rowids"), this is relatively expensive. In general to get the same performance as the three … WebSep 14, 2015 · ALTER INDEX xyz REBUILD TABLESPACE TS_INDX01 NOLOGGING PARALLEL 8; I am using NOLOGGING and PARALLEL thinking it will speed-up the movement process. But now I am confused because I think it will change the property of the index also, as in, when we create an index we specify some parallel and logging properties. So I want … date french day 2023
Adding columns to existing index in Oracle - Stack Overflow
WebDec 3, 2011 · Adding columns to existing index in Oracle. I have a relatively large table (81M rows) and an index on it. I want to add a column to the existing index. I searched for it on … WebAfterward you can either rebuild the index or specify another ALTER INDEX statement with the ENABLE keyword. UNUSABLE Clause . Specify UNUSABLE to mark the index or index … WebAug 10, 2024 · create index i on tab ( col1, col2, col3 ); And your where clause is: Copy code snippet. where col3 = 'value'. To use the index the database either has to wade through all the values in col1 and col2. Or, more likely, read the … bivvy pet insurance reviews 2019