![]() The following query returns information from the DMVs (Dynamic Management Views) related to Missing indexes, which report the list of indexes that the Query Optimizer points out as necessary in order to improve the current average workloads. Proper indexing drastically reduces the time and read IOPS needed to query data. EXEC sp_executesql - remove the comment on the beginning of this line to run the commandsįETCH NEXT FROM updatestats INTO updatestatsĪfter several hours of normal activity, check to see if the SQL engine reports any missing indexes. PRINT - comment this print statement to prevent it from printing whenever you are ready to execute the command below. SET = 'UPDATE STATISTICS ' + '' + '.' + '' + ' WITH FULLSCAN' remove the comments from EXEC sp_executesql in order to have the commands actually update stats, instead of just printing them. This will update all the statistics on all the tables in your database. It could be necessary to update them daily, every other day, or weekly.Ĭonnect to your database and run the following to update all stats in the database in one step. We recommend updating stats on a regular basis based on how often data changes or is inserted. This data is used by the SQL query optimizer to select an execution plan for the queries, and it’s vital that the statistics are updated to get effective execution plans. Run against the database with the performance issueġ.- Update all your tables data distribution statistics, with a 100% sampling rate (Fullscan). It will provide a more granular view of the resource percentages used as it is broken into 15 second intervals. Unlike the above query, this one only provides information for the past hour on resource usage and must be ran directly against the database. Where database_name = 'your_database_name' ![]() This query will give you the 5 minute averages of resource usage for the database(s) so you can see if there was an extended timeframe of resource usage or the size of the database. Moreover, to monitor the database for high DTU components usage (CPU, LogIO, DataIO) you can use the following DMVs: Monitor performance using DMVs - Azure SQL Database & SQL Managed Instance The below article goes in detail how to identify performance issues, if you notice degradation on your database performance. At least until you’re able to bring the situation under control bear in mind, these recommendations will increase the DTU consumption, which it is suggested to increase the service tier while you complete your maintenance routine or perform it during a time of the day (or night) in which your application doesn’t require the horse-power. ![]() The recommendation is for your maintenance routine to include the below action plan which includes updating statistics, finding missing indexes and frequent monitoring, or increase the service level to add more hardware capabilities to your database, while you work to decrease the work load footprint on your database. To solve this, there are at least two different ways to approach this situation. Additionally, this would also apply if your database were on a vCore service tier as the same internal metrics are used. In average, 80% – 90% of the performance related support cases I have been involved in, are created due to a non-existent maintenance plan or even the awareness said plan is needed.Īzure SQL Database unit of measure is DTU (Data Transaction Units), which is composed of CPU, LogIO and DataIO, the closer to 100% of consumption any of these DTU components get, the more issues your databases will experience. I am a firm believer that there is no SQL Database unable to keep up with any given workload, but a poorly designed maintenance plan. Updating statistics and finding missing indexes, are among other performance tuning database methods, mainly recommended to help you decrease the number of logical reads and improve general database performance. The less logical reads your queries make, the less resource consumption will be required from an Azure SQL Database. Azure SQL Database requires that end users update statistics and find missing indexes with certain frequency, according to how much data manipulation happens on their tables. Many believe Azure SQL Database will have optimal performance due to its proven versatility on various environments, however, that's not always the case. In addition, it will refer to various public documents that can complement the actions described in this article. This article will guide you through a series of recommendations to improve performance on your database. ![]()
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