About Table Partitioning Partitioning does not change the physical distribution of table data across the segments. Table distribution is physical: Greenplum Database physically divides partitioned…
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Tag: performance
How to measure performance of PostgreSQL Database Server(s)?
The benchmark test is designed to evaluate and compare the performance of different configurations, topologies, systems and components. For this purpose I will use the…
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Speeding Up “min” and “max” functions in postgresql
Indexes are a perfect tool to finding a certain value or some kind of range in a table. It is possible to speed up a…
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Partitioning Existing Tables in Postgres
So, your database is growing rapidly, as, ideally, is your business. The problem is, its performance is getting worse. You’re starting to wonder whether partitioning…
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Oracle CBO is ignoring SYS_DL_CURSOR
Some days ago i came across with a pl/sql code where they used (for some reason) an Oracle hint called SYS_DL_CURSOR. I got it when i…
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APPEND_VALUES and SYS_DL_CURSOR Hints with HCC
The APPEND_VALUES hint was introduced in 11.2 to allow direct path inserts with variables using the VALUES clause. i.e. INSERT INTO XYZ (COL1, COL2) VALUES…
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PostgreSQL “bind variable peeking”
custom vs. generic plans With my Oracle database background, I know how important it is to balance the pros and cons of using bind variables…
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Postgresql PREPARE — prepare a statement for execution
Synopsis PREPARE name [ ( data_type [, …] ) ] AS statement Description PREPARE creates a prepared statement. A prepared statement is a server-side object that…
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How to Swap SQL_Profiles?
The central idea behind “swapping” SQL profiles is simple. You define a SQL profile that specifies the SQL statement that you want to tune, and an…
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SQL Profiles in the Data Dictionary
In the paper SQL Profiles (page 22) I described the data dictionary tables where the hints belonging to SQL profiles are stored. For example, with the following…
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