docs/document/content/user-manual/common-config/props.en.md
+++ title = "Properties Configuration" weight = 1 chapter = true +++
Apache ShardingSphere provides the way of property configuration to configure system level configuration.
| Name | Data Type | Description | Default Value |
|---|---|---|---|
| sql-show (?) | boolean | Whether show SQL or not in log. | |
| Print SQL details can help developers debug easier. The log details include: logic SQL, actual SQL and SQL parse result. | |||
Enable this property will log into log topic org.apache.shardingsphere.sql, log level is INFO | false | ||
| sql-simple (?) | boolean | Whether show SQL details in simple style | false |
| kernel-executor-size (?) | int | The max thread size of worker group to execute SQL. One ShardingSphereDataSource will use a independent thread pool, it does not share thread pool even different data source in same JVM | infinite |
| max-connections-size-per-query (?) | int | Max opened connection size for each query | 1 |
| max-union-size-per-datasource (?) | int | Max union size per datasource for aggregate rewrite. When route units count for a datasource exceeds this value, they will be split into batches to restore parallel execution capability | Integer.MAX_VALUE |
| check-table-metadata-enabled (?) | boolean | Whether validate table meta data consistency when application startup or updated | false |
| load-table-metadata-batch-size (?) | int | The number of table metadata loaded at a time when application startup or refreshes table metadata | 1000 |
props:
sql-show: true
The default value of the max-connections-size-per-query configuration is 1, meaning each query request can only use one connection per database instance. If you adjust this parameter to enable memory-restricted mode (see Memory-Strictly Mode for details), ensure that your database's JDBC implementation supports streaming queries or can enable them. For example, in MySQL, you need to set statement.setFetchSize(Integer.MIN_VALUE) to achieve streaming queries.
The example of ShardingSphere warehouse contains property configurations of various scenarios. Please refer to: https://github.com/apache/shardingsphere/tree/master/examples