This section includes advanced querying topics such as using query indexes, using query bind parameters, querying partitioned regions and query debugging.
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This topic covers considerations for improving query performance.
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Monitoring Low Memory When Querying
The query monitoring feature prevents out-of-memory exceptions from occurring when you execute queries or create indexes.
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Timeouts for Long-Running Queries
Configure a timeout value for long running queries, such that they do not complete, and Tanzu GemFire throws an exception when a query runs for longer than the configured value.
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Using query bind parameters in Tanzu GemFire queries is similar to using prepared statements in SQL where parameters can be set during query execution. This allows you to build a query once and execute it multiple times by passing the query conditions during run time.
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A query may return different results depending on the member on which it is executed.
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Tanzu GemFire allows you to manage and store large amounts of data across distributed nodes using partitioned regions. The basic unit of storage for a partitioned region is a bucket, which resides on a Tanzu GemFire node and contains all the entries that map to a single hashcode. In a typical partitioned region query, the system distributes the query to all buckets across all nodes, then merges the result sets and sends back the query results.
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You can debug a specific query at the query level by adding the
<trace>keyword before the query string that you want to debug.
