Fast SPLIT PARTITION operation is unusually slow

I recently observed that the total time taken to split an empty partition, in 10.2.0.5, has increased by many fold—i.e. from under 30 seconds to 60 minutes. SPLIT PARTITION operation is, simply, creating two new partitions and redistributing the rows from the partition being split into the two new partitions. Often one new partition contains …

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Computing Oracle SQL_ID and HASH_VALUE

I needed an hash function, in Java, which is simple, practically less collision and provides a short alphanumeric or an unsigned number as hash for any string or text. I stumbled upon few blog posts that explain how Oracle SQL_ID and HASH_VALUE are calculated by database engine, concisely and elaborately; also implementations in Python and …

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Deprecated SQL*Plus Commands in Oracle 11g R2

This just a short note to point out that the below SQL*Plus commands are deprecated as of Oracle 11g R2, but available in the current release of SQL*Plus for backward compatibility. The documentation states that this may only be available by setting the SQLPLUSCOMPATIBILITY variable in the future releases.  You should modify scripts using obsolete …

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Eliminating “Us And Them”: Making IT and the Business One

Eliminating “Us And Them”: Making IT and the Business One is for anyone who is interested in knowing the divide between IT and business. It is a must read for IT professionals and business persons in your company. This book has 25 chapters, they are: 1.  Us and Them 2. When IT is “Us” and …

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RECORD feature of TKPROF

This is just a short note the point out that RECORD option of TKPROF is extremely useful in recording and capturing the non-recursive SQL statements in the order of execution from the SQL trace file.  I have not had a requirement to use it until—today—one of my developers lost the original test script used when …

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SQL*Plus Feature: TIMING and SET TIMING command

SET TIMING—one of the most frequently used commands—displays timing statistics on each SQL command or PL/SQL block. What if you want to collect timing statistics for multiple group of statements? TIMING command becomes handy in such situation—one of things that I knew and have forgotten over time. It can be used to collect data to do …

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SQL returns wrong result when the table order is swapped

I noticed a strange behavior—a SQL statement, which used to return no rows in the past, started returning rows in an environment where the test data set has not changed. I performed a code comparison and observed a difference in the order of a table in FROM clause. After looking through, I found a bug entry on MOS …

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The Art of Scalability: Scalable Web Architecture, Processes, and Organizations for the Modern Enterprise

The Art of Scalability: Scalable Web Architecture, Processes, and Organizations for the Modern Enterprise—A must read for technical and business persons in your company, if you are looking to scale your business, whether you are a startup or Fortune 500. Scalability is widely used term, often, refers to scaling a specific technology—for most technical people. …

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