Entries by Arsalan

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The following figure illustrates the phases, and the iterative nature, of a machine learning project. The process flow shows that a machine learning project does not stop when a particular solution is deployed. Instead, the results trigger new business questions, which can be used to develop more focused models.


Formatted view on V$LOCK that created via $ORACLE_HOME/rdbms/admin/catblock.sql SESSION_ID == SID in V$LOCK LOCK_TYPE, LOCK_ID1, LOCK_ID2 formatted value of TYPE, ID1, ID2 from V$LOCK MODE_HELD and MODE_REQUESTED formatted value of LMODE and REQUEST from V$LOCK LAST_CONVERT == CTIME of V$LOCK BLOCKING_OTHERS formatted value of BLOCK from V$LOCK Reference: https://docs.oracle.com/en/database/oracle/oracle-database/19/refrn/DBA_LOCK.html#GUID-B19FF191-AC89-498D-B2C1-2A18F63DC03D

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V$TRANSACTION lists the active transactions in the system. (i) The following columns together point to a transaction. (i.e.) The combination of the following should give a unique transaction id for that database. XIDUSN – Undo segment number XIDSLOT – NUMBER Slot number XIDSQN – NUMBER Sequence number (ii) The following columns explain the number of […]

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Oracle BUG DB RU or DB RUR

After applying DB RU or DB RUR, you may notice that the Block Change Tracking (BCT) file is getting created of a size that is not in line with the database size. Oracle recommends that you apply interim one-off Patch 33185773 to correct this problem(s) in the RU/RURs indicated above. Note the fix for this issue has […]

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Oracle CBO performs transitivity as the first step in optimization. Transitivity means generating additional predicates based on existing predicates. The main advantage is the inclusion of extra access methods. Transitivity is not done for join predicates. Assume A, B, and C are columns. If A=5 and A=B, you can conclude that B=5. This can be […]

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Oracle Multitenant: LICENSE CHANGES IN 2019

For all offerings using Oracle Database 19c or later, if you are not licensed for Oracle Multitenant, then you may have up to 3 user-created PDBs in a given container database at any time. For all offerings using Oracle Database 12.1 through 18c, if you are not licensed for Oracle Multitenant, then the container database […]