DROP DATABASE no longer drops non-empty databases unless the CASCADE modifier is added. #17926
The --cache and --max-sql-memory flags for the cockroach start command now default to 128MiB instead of 25% of physical memory to avoid using too much memory by default. Production deployments are encouraged to set --cache explicitly to 25-50% of the memory allocated to CockroachDB for best performance. #18040
SQL Language Changes
The new IMPORT TABLE statement provides a fast way to import an entire table's data into CockroachDB by loading CSV files. Although this feature uses CCL-licensed code, and is therefore available only in builds that include CCL-licensed code, using it is free and does not require an enterprise license. #17539
The DELETE and UPDATE statements now support ORDER BY and LIMIT clauses. #18023
The sql_safe_updatessession variable can be set to disable certain "dangerous" SQL statements, such as DELETE or UPDATE without a WHERE clause. This is set by default in the cockroach sql shell. #17604#17889
Parsing of the DATE type is no longer affected by the session time zone. #18164
Type hints are now permitted even when they are imprecise, improving compatibility with some drivers and frameworks. #16672
Untyped string literals can now be implicitly cast to numbers, improving compatibility with Javascript clients. #15903
The CANCEL, RESUME, PAUSE, BACKUP, RESTORE, and IMPORT statements are now valid in prepared statements. The SET statement now supports placeholders for values in prepared statements. #17805#17591
Command-Line Interface Changes
Fatal error messages are now printed to both stderr and the logs. #17588
The cockroach dump command correctly represents values such as NaN and Inf. #18031
The cockroach sql shell now supports a \h command for "help". Context-sensitive syntax help is available by typing a question mark followed by the tab key while typing a command. #13540
The cockroach sql shell now sets a default application_name of cockroach. #17602
The cockroach sql shell now prints hints and warnings when available from the server. #17604
The cockroach sql shell has new debugging options \set echo (and an equivalent command-line flag --echo-sql) and \unset smart_prompt. #18127
Admin UI Changes
Various debugging pages are now available at /#/debug. #17635
The Live Bytes per Store graph has been replaced with Logical Bytes per Store, which includes the size of old MVCC values waiting to be garbage collected. #17782
The /debug/vmodule/ endpoint has been removed; use the SQL function crdb_internal.set_vmodule() instead. #17792#17914
Local tracing is now always enabled when nodes start up (even though it will be disabled by default when the node is fully initialized). This helps diagnose problems that keep a node from joining its cluster. #17944
Various adjustments to fonts and margins. #16773#17673
Bug Fixes
Fixed a regression in the command queue (introduced in alpha-20170810) that could result in data inconsistencies. #17939
Fixed a bug in range quiescence that could result in some ranges getting stuck indefinitely. #18184
Foreign keys that point to a prefix of an existing index now work correctly. Previously, rows could be deleted from the referenced table without recognizing the constraint violation if rows in the referring table pointed to them. These foreign keys are also now shown correctly in SHOW CREATE TABLE. #17638
Fixed a bug in ReverseScan that could cause data to be missing from query results. #17868
Fixed a flow control leak that could lead to deadlock. #17856
Parallelized queries now handle retryable errors correctly. #17627
Nodes now panic if they fail a consistency check. The server.consistency_check.intervalcluster setting replaces the COCKROACH_CONSISTENCY_CHECK_INTERVAL environment variable for configuring the consistency checker. #17853
Added overview pages for the ALTER DATABASE and ALTER INDEX statements that point to pages for relevant subcommands, e.g., RENAME DATABASE and RENAME INDEX. #1869
Updated the Contribute to CockroachDB to provide guidelines on finding a project, determining its complexity, and learning what to expect in your collaboration with the Cockroach Labs team. #1881
Enterprise Edition Changes
The initial split/scatter phase of large RESTORE jobs is now much faster. #18043
End times are now recorded correctly in backup descriptors. #17908
Avoided slowdowns when multiple backup/restore goroutines attempt to update their progress simultaneously. #17934
RESTORE now uses larger SSTables to avoid running out of file descriptors. #17991#18037