We have seen “enq: UL – contention” wait event a couple of times in our Oracle Database. It occurs when there is contention for an…
Leave a CommentCategory: DATABASE
High I/O (Input/Output) activity in an Oracle Database can indicate that the system is under heavy load and this may lead to performance issues. High…
Leave a CommentThe ORA-30036 error is a common issue that can occur in an Oracle Database when the system is unable to extend a segment by a…
Leave a CommentOracle Exadata is a high-performance database machine that combines the power of Oracle Database software with the speed and scalability of industry-standard x86 servers, InfiniBand…
Leave a CommentBelow are some interesting conceptual points regarding Oracle Multitenant CD-PDB Architecture which can prove useful for DBA who is new to Oracle multi-tenant architecture. This…
Leave a CommentYou can utilize Oracle Database dynamic performance views to query important tuning related parameters like memory utilization, Disk I/O, Disk structure etc. These dynamic performance views are special views that are continuously updated while a database is open and in use.
Note that the actual dynamic performance views are identified by the prefix V_$. Public synonyms for these views have the prefix V$. You should access only the V$ objects, not the V_$ objects.
Leave a CommentBelow are some of the frequently used commands related to Transparent Data Encryption (TDE)
— TO FIND WHICH ALL TABLESPACES ARE ENCRYPTED
SQL> select * from dba_tablespaces where encrypted='YES';
OR
SQL> select * from V$ENCRYPTED_TABLESPACES;Leave a Comment
Keeping data secure is one of the primary job of DBA. Oracle’s Transparent Data Encryption Tablespace Encryption option of Oracle Database 11g Enterprise Edition provides an excellent method to encrypt data at rest. This option works perfectly with Oracle EBS R12.
The TDE Tablespace Encryption option can be used to encrypt the tablespaces that store the content of your E-Business Suite application so you can encrypt the database files and any backups of these files. Good thing about TDE is you do not have to change any of your existing code as TDE is transparent to application.
3 CommentsA well-planned methodology is the key to success in performance tuning. Without a proper diagnosis of the issue any troubleshooting step taken will further delay the resolution. Example, a DBA can not just blindly start tracing/tuning a SQL/Sessions when all symptoms on careful analysis points towards issues with DIsk/Memory/Network etc.
2 CommentsHistogram helps Oracle Optimizer in generating a better execution plan specially when the data is highly skewed in the table. You can say a histogram is an optional special type of column statistic data that provides more detailed information about the actual data distribution in a table column.
Before going into Oracle Histograms details, let us understand what it Histogram in simple language.
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