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Often, when the global temporary tables are in use in batch processing, we have lot of problems regarding plan stability. For example A session inserting 1 row in a global temporary table based on some other table joins Another session which were apparently doing the same insert but will try to insert 1000 rows […] Before to 12c, we have a problem to revert back to a question, how much time does the statistics operation will run? This is common problem, as we cannot anticipate the time and its depend on the various factors that will take place at time of statistics job execution. To accomplish this we will have […] Previous to 12c, when you want to perform an monitoring the Session you will have to turn the trace etc or trace with application/module/program/sql_id etc. But, what if you want to monitor specific operation for that session not whole or application. Kind of set of operations you want to peform not all with in that […] From 12c onwards, Oracle optimizer maintains the directives that influence the optimizer to take appropriate decision while executing the statement or estimation. As you read from previous posts, Optimizer maintains the execution statistics now,they can be used to create a directive for future executions. These directives can be used by optimizer and determine which optimization […] If you have read the previous post on automatic query reoptimation, this post is the continuation of the same, by looking them closely. All the examples used are from oracle white paper. Parameters that influence optimizer to use adaptive features SQL> show parameter adaptive NAME TYPE VALUE ———————————— ———– —————————— optimizer_adaptive_features boolean FALSE optimizer_adaptive_reporting_only boolean […] From 12c, interval partitions has been enhanced to use reference partitioning, With this you can create a parent/child table with references in them using interval partitioning. The following is the test case. Create table EMPLOYEE ( EMPLOYEE_ID number primary key, EMPLOYEE_NAME varchar(25), JOINING_DATE date) PARTITION BY RANGE (JOINING_DATE) INTERVAL (NUMTOYMINTERVAL(1,’YEAR’)) ( PARTITION P_2013_06 VALUES LESS […] From 12c, you can truncate partitions from a referenced partition with cascade option. The following is the test case. Create table EMPLOYEE ( EMPLOYEE_ID number primary key, EMPLOYEE_NAME varchar(25), JOINING_DATE date) PARTITION BY RANGE (JOINING_DATE)( PARTITION P_2013_06 VALUES LESS THAN (to_date(’30-06-2013′,’dd-mm-yyyy’)) NOCOMPRESS, PARTITION P_2013_07 VALUES LESS THAN (to_date(’31-07-2013′,’dd-mm-yyyy’)) NOCOMPRESS, PARTITION P_2013_08 VALUES LESS THAN (to_date(’31-08-2013′,’dd-mm-yyyy’)) […] Before to 12c, if you want to maintain partitions you will need to execute that many alter statements partition commands that many times. For example to add p7,p8 partitions, you have to use SQL> alter table test_tbl add partition p7 values less than (7) SQL> alter table test_tbl add partition p8 values less than […] Before to 12c, it is not possible to create a index for certain partitions or for the partitions you want. From 12c onwards, you can create the indexes (global or local) for specific partitions (not to all partitions) or for specific sub partitions (not to all sub partitions). This means indexes will be created […] From 12c onwards, partitions movement has been extended with "online clause", along with this global index are maintained during partition maintenance , hence manual rebuild of index is not required any more. Before proceeding with the test, here are some restriction as listed in documentation, ONLINE clause can’t be specified ?for tables owned by […] |
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Oracle 23c New Features for DBA's
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