Category Archives: Oracle Internal

APPROX_COUNT_DISTINCT in Oracle 12c.

Most of time during performance analysis to understand Stale stats, we usually need to check estimated NDV (Number of Distinct values). If data-set is huge , it take considerable time to project desired output using traditional COUNT(DISTINCT) appraoch. For any … Continue reading

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Lateral Views in Oracle 12c.

#TGIF. In Oracle 12c, we got introduce to LATERAL Views officially(Before same was getting use internally as part of Query Transformation) to join Inline views, Pre 12c we were not able to achieve same of joining inline views. With Lateral … Continue reading

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#SQLSERVERLearning : Column Data Type Conversion in Oracle and SQL Server.

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 finding or Observations with SQL Server … Continue reading

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MIN , MAX and INDEX Access in Oracle.

All Entries in Index are stored as sorted either in ascending or descending order. If we need MIN or MAX for any column being indexed, its should be easier for oracle to fetch same as both would be at index … Continue reading

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#SQLSERVERLearning : String Concatenation for NULL and Empty String in Oracle and SQL Server

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 finding or Observations with SQL Server … Continue reading

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Posted in Oracle Internal, SQL Server Learning | Tagged , , , , , , | 2 Comments

Interesting Database SQL Concept Question, Give it a try??

#TGIF Today’s will try to walk you through a Database concept questions and hopefully you will learn something new. (Obviously if you are not aware of it.!) Suppose we have below scenarios, In Database Session 1 : –> we are … Continue reading

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Posted in Helper SQL, Oracle Internal | Tagged , , , , , | 4 Comments

Multiplication across rows and Analytical Functions.

Oracle or SQL Server provide Aggregation functions for MIN/MAX/COUNT/SUM, but suppose a scenario when we want multiplication of rows across a partition or complete table. Database does not provide any buildin function to achieve same. Suppose we have below expectations, … Continue reading

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Posted in Helper SQL, Oracle Internal, SQL Server Learning | Tagged , , , , , | 1 Comment

Aggregate Function , Distinct and NULL Values in Oracle.

While working on SQL Server with queries having aggregation got a warning message. “Warning: Null value is eliminated by an aggregate or other SET operation.” So thought let write up something on Aggregation and NULL Values for Tradition RDBMS for … Continue reading

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#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