Updating index on oracle table
You can also perform more complicated updates in Oracle.You may wish to update records in one table based on values in another table.You can disable a function-based index with this command: The landmark book "Advanced Oracle SQL Tuning The Definitive Reference" is filled with valuable information on Oracle SQL Tuning.This book includes scripts and tools to hypercharge Oracle 11g performance and you can buy it for 30% off directly from the publisher.
You can buy it direct from the publisher for 30%-off and get instant access to the code depot of Oracle tuning scripts.” by Markus Winand is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 Unported License.the operation (see Updating Indexes Automatically), so that they remain available throughout.Simply including the existing state of the SET clause can result in a huger performance improvement for UPDATE statements: As more people adopt 64-bit servers with giant data buffers, we see a delay caused by the database writer process having to scan through giant data buffers seeking dirty blocks.Many shops are replacing their platter-style disks with solid-state disks, and creating a very small data buffer, just for the updates.Since you can't list more than one table in the Oracle UPDATE statement, you can use the Oracle EXISTS clause. MD_DT DESC) AS ROW_ID FROM t2, t1 WHERE t2.x = 'x' AND t2.y = 'y' AND t2.After your first truncate, the index needs to be rebuilt - it can't be updated, it's already "broken" and unavailable.Oracle won't rebuild it automatically for the next operation you do on the table, even if you include the update clause.Disable an Oracle index Question: I want to disable an Oracle index. Answer: First, why do you want to disable an index?If you are doing batch loads, the proper procedure is to drop and then re-create the index.