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Lens –

Jdbc driver configuration


The configuration parameters and their default values
No. Property Name Default Value Description
1 lens.cube.query.driver.supported.storages List of comma separated storage names that supported by a driver. If no value is specified, all storages are valid
2 lens.cube.query.enable.multi.table.select false Tells whether multiple tables are allowed in from clause of final HQL query
3 lens.cube.query.partition.where.clause.format yyyy-MM-dd HH:mm:ss The simple date format of how the queried partition should be put in where clause. If nothing is specified, it will use the format from org.apache.lens.cube.metadata.UpdatePeriod for each type of partition
4 lens.cube.query.replace.timedim false Tells whether timedim attribute queried in the time range should be replaced with its corresponding partition column name.
5 lens.cube.query.time.range.writer.class org.apache.lens.cube.parse.BetweenTimeRangeWriter The timerange writer class which specifies how the resolved partitions in timeranges should be written in final query. Available writers are org.apache.lens.cube.parse.ORTimeRangeWriter and org.apache.lens.cube.parse.BetweenTimeRangeWriter
6 lens.driver.jdbc.connection.provider A contract for obtaining JDBC connections
7 lens.driver.jdbc.db.password The database user's password
8 lens.driver.jdbc.db.uri JDBC connection URL in the format jdbc:dbms://host:port/dbname
9 lens.driver.jdbc.db.user The database user on whose behalf the connection is being made
10 lens.driver.jdbc.driver.class com.mysql.jdbc.Driver Type of JDBC driver used to connect backend database
11 lens.driver.jdbc.enable.resultset.streaming.retrieval false Flag to enable row by row retrieval of result set from the database server. This is used to enable streaming result sets for MySQL. This is set to false by default.
12 lens.driver.jdbc.explain.keyword Explain Explain keyword used to get the query plan of underlying database
13 lens.driver.jdbc.fetch.size 1000 Fetch size for JDBC result set
14 lens.driver.jdbc.get.connection.timeout 10000 Response timeout in milliseconds of any JDBC call invoking data transmission over a connection socket
15 lens.driver.jdbc.pool.idle.time 600 Maximum idle time in sec before a connection is closed
16 lens.driver.jdbc.pool.max.size 15 Maximum number of concurrent connections allowed in pool
17 lens.driver.jdbc.pool.max.statements 20 Maximum number of prepared statements to cache per connection
18 lens.driver.jdbc.query.rewriter org.apache.lens.driver.jdbc.ColumnarSQLRewriter Rewriting the HQL to optimized sql queries