2019-12-13
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Constants vs. Parameterless Functions

Do you use parameterless PL/SQL functions in your queries? Did you know that this may cause performance issues? In this blog post I explain why parameterless functions can be the reason for bad execution plans in any Oracle Database. I recently had to analyze this problem in a production system and thought […]
2019-02-17
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MemOptimized RowStore in Oracle Database 19c

Since February, 13 2019 Oracle Database 19c is available. I blogged about this feature here and here. Time for an update. So, what’s new in 19c regarding the MemOptimized Rowstore? Fast Lookup Works with JDBC Thin Driver I listed 16 prerequisites for the MemOptimized Rowstore in this blog post. The last one – “The […]
2018-06-19
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MemOptimized RowStore in Oracle Database 18c with OCI

On June, 10 2018 I blogged about the MemOptimized RowStore in Oracle Database 18c. If you haven’t read this post, it is a good idea to catch up now. I showed that accessing a memoptimized table t4 via the MemOptimized RowStore was around 60% slower than accessing a heap-organized table t1. I […]
2018-06-10
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MemOptimized RowStore in Oracle Database 18c

The MemOptimized RowStore introduced in Oracle Database 18c is designed to improve performance of simple queries accessing data via primary key columns only. An example of such a query is SELECT value FROM t WHERE key = :key where key is the only primary key column of table t. This feature is available […]
2012-12-23
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Building Comma Separated Values with Oracle & SQL

From time to time I’m asked to aggregate strings from multiple records into a single column using SQL. Here’s an example, showing a comma separated list of ordered employee names per department based on the famous EMP and DEPT tables. Oracle introduced the aggregate function LISTAGG for that purpose in 11.2. If […]
2012-12-02
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Apple iPad Camera Connection Kit – What’s faster USB or SD Card?

I’ve just bought a Sony DSC RX100 camera with an Apple iPad Camera Connection Kit. The kit contains an USB adapter and a SD Card adapter. I intend to copy photos to my iPad for review and backup purposes during my holidays. My son argued that the SD card adapter must be […]