Release 340 (8 Aug 2020)#
General#
- Add support for query parameters in - LIMIT,- OFFSETand- FETCH FIRSTclauses. (#4529, #4601)
- Add experimental support for recursive queries. (#4250) 
- Add - bitwise_left_shift(),- bitwise_right_shift()and- bitwise_right_shift_arithmetic(). (#740)
- Add - luhn_check(). (#4011)
- Add - IF EXISTSand- IF NOT EXISTSsyntax to- ALTER TABLE. (#4651)
- Include remote host in error info for page transport errors. (#4511) 
- Improve minimum latency for dynamic partition pruning. (#4388) 
- Reduce cluster load by cancelling query stages from which data is no longer required. (#4290) 
- Reduce query memory usage by improving retained size estimation for - VARCHARand- CHARtypes. (#4123)
- Improve query performance for queries containing - starts_with(). (#4669)
- Improve performance of queries that use - DECIMALdata type. (#4730)
- Fix failure when - GROUP BYclause contains duplicate expressions. (#4609)
- Fix potential hang during query planning (#4635). 
Security#
- Fix unprivileged access to table’s schema via - CREATE TABLE LIKE. (#4472)
JDBC driver#
Elasticsearch connector#
- Fix failure when index mapping is missing. (#4535) 
Hive connector#
- Allow creating a table with - external_locationwhen schema’s location is not valid. (#4069)
- Add read support for tables that were created as non-transactional and converted to be transactional later. (#2293) 
- Allow creation of transactional tables. Note that writing to transactional tables is not yet supported. (#4516) 
- Add - hive.metastore.glue.max-error-retriesconfiguration property for the number of retries performed when accessing the Glue metastore. (#4611)
- Support using Java KeyStore files for Thrift metastore TLS configuration. (#4432) 
- Expose hit rate statistics for Hive metastore cache via JMX. (#4458) 
- Improve performance when querying a table with large files and with - skip.header.line.countproperty set to 1. (#4513)
- Improve performance of reading JSON tables. (#4705) 
- Fix query failure when S3 data location contains a - _$folder$marker object. (#4552)
- Fix failure when referencing nested fields of a - ROWtype when table and partition metadata differs. (#3967)
Kafka connector#
MongoDB connector#
- Add - mongodb.max-connection-idle-timeproperties to limit the maximum idle time of a pooled connection. (#4483)