Tag Archives: Oracle

#SQLSERVERLearning : Exception on Invalid/Incorrect Hints?

All my blogs with #SQLSERVERLearning is intended to cover all stuff identified as difference between Oracle and SQL Server. Hopefully it might be helpful for Oracle guy also working in SQL Server world. All findings or Observations with SQL Server … Continue reading

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#SQLSERVERLearning : Does Unique Index Stored NULL Values in Index?

All my blogs with #SQLSERVERLearning are intended to cover all stuff identified as difference between Oracle and SQL Server. Hopefully it might be helpful for any Oracle guy also working with SQL Server. All finding or Observations with SQL Server … Continue reading

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Posted in Oracle Internal, SQL Server Learning | Tagged , , , , , | Leave a comment

#SQLSERVERLearning : Changing Short Cut in SQL Server for Query Execution.

All my blogs with #SQLSERVERLearning is intended to cover all stuff identified as difference between Oracle and SQL Server. Hopefully it might be helpful for Oracle guy also working in SQL Server world. In SQL Developer for running any SQL … Continue reading

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Posted in SQL Server Learning | Tagged , , , | 1 Comment

#SQLSERVERLearning : Alias are mandate for inline views

New challenge added to my career life – Microsoft SQL Server.! Now need to work on multiple database along with Oracle (My Fav) as primary. Most of folks feel , both are traditional RDBMS database and should or need to … Continue reading

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Analytical Function at Rescue

With Analytical function in oracle, we can leverage very powerful data projections for complex data requirement. It exhibit great tool to play around group sets with in a window and achieve desired outcome. Will walk¬†¬†through one of requirement which application … Continue reading

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Posted in Helper SQL | Tagged , , | 1 Comment

Gather Stats on Function based filter condition in oracle

For one of performance improvement, identify root cause for bad execution plan was incorrect cardinality estimation on function based condition on a table column. As part of recommendation, we just needed to get estimated cardinality improve on table filter conditions. … Continue reading

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Alias on Rownum might degrade performance in oracle.

We use First’s row filtering(using Rownum) for lot of day to day functional implementation, Pagination being one of the best example. Rownum clause is best way to impose First – N Rows optimization and restrict subset of projected rows as … Continue reading

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Incorrect Refer to a column alias causing performance degradation

For easy of referencing and better code readability we add aliases to table reference in most of queries. For correlated queries we add conditions based on correlation columns between any two tables or entities. Below is one of query shared … Continue reading

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NVL Function Internal Behaviour in Oracle for Scalar Calls.

During a performance analysis, identified a NVL Scalar Function calls was eating up lot of SQL time. Scalar function was like below, NVL ( A_Table_Column, (SELECT COUNT(*) FROM TABLE_B WHERE <>) ) If we check Scalar Columns, we are ideally … Continue reading

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Basic Understanding of Autonomous Transaction in Oracle

Most of us are aware of Use of Autonomous transactions in oracle and what benefit it exhibit. just to elaborate on same, It help to Perform SQL operations(Especially committed DML) independent of primary transaction. In precise, Its shares no lock … Continue reading

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