Enabling auto update statistics for a Synapse dedicated SQL pool

Hey there pmscorca

Thats a good question and thanks for using QandA platform

So enabling auto-update statistics in Azure Synapse Analytics is good for maintaining query performance.

But, whether you should enable this option depends on lott of factors such as the type of ur workload, the frequency of data changes, and the performance and requirements of your queries and etc. so I say it totally depends.

If this helps kindy accept the answer thank much.

Hi @pmscorca
Welcome to Microsoft Q&A platform and thanks for posting your question here.

In Azure Synapse Analytics, statistics are used by the query optimizer to estimate the number of rows in a query result. This estimation is important because it helps the system create a plan to make the query run faster. The query optimizer uses statistics to determine the best way to retrieve data from tables and indexes, and to join tables together.

By default, statistics are updated automatically when a table's data changes by 20% or more. This means that if a table has 100,000 rows, statistics will be updated automatically when the table's data changes by 20,000 rows or more. However, you can choose to update statistics more frequently by turning on the "auto update statistics" option. This option ensures that statistics are always up-to-date and can help queries run faster. 

Enabling auto update statistics for Synapse dedicated SQL pools is recommended as it helps to keep the statistics up-to-date and ensures that queries run efficiently. For very large tables with many columns and statistics, it may be better to update only the necessary statistics to save time and resources.

Reference
https://video2.skills-academy.com/en-us/azure/synapse-analytics/sql/develop-tables-statistics
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