Overview of Changes

[IMPORTANT] This version includes a backward incompatible file format change for YSQL. This means that if you have an existing cluster with YSQL schema, then you will not be able to connect to the YSQL database after upgrading to v1.3.1. There are two ways to work around this problem:

• If you don't care about preserving your existing data, then you can delete your older cluster, upgrade to v1.3.1 and create a new cluster.
• If you want to continue using your existing data, then please save your older data (in the form of SQL statements), delete the older cluster, upgrade to v1.3.1, create a new cluster and then load the previously saved data.

YSQL Changes

• [YSQL] Fix error in nextval_internal retry.#1783
• [YSQL] Support bulk inserts for COPY FROM command.#1590
• [YSQL] Support for Triggers and Extensions.#1156
• [YSQL] Simplify gflags enabling YSQL.#1691
• [YSQL] Support NULLS LAST for SELECT.#1734

System Improvements

• Extra cleanup of intents of aborted transactions to prevent repeated log messages.#1722
• Cleanup checkpoints on startup.#498
• Unified yb::RandomAccessFile and rocksdb::RandomAccessFile.#1661
• Clear Pending Delete State on RPC Failure.#424
• Do not crash yb-master process if we fail to find a namespace when listing tables.#1716
• Allow consecutive master restarts to succeed.#1074
• Change soft memory limit handling.#1437
• Use log prefix in MvccManager.#1835
• Fix handling timeout of a local call in the service.#1866
• Fixed TS crash due to NULL name in the PTBindVar object.#1821
• Add /tables view to tablet server ui.#1830
• Add ability to avoid using the compaction thread pool for flushes.#1874
• Tablet leader tracking at catalog manager.#1881
• Allow in memory erase of intents.#1240
• Fix assignment order of propagated_safe_time and propagated.#1889
• Memory monitor should not flush tablet that is already flushing.#1880
• Fixed potential race condition in memory-based flush.#1859