DuckDB 0.2.6 release notes

This preview release of DuckDB is named "Jamaicensis" after the blue-billed Ruddy Duck (Oxyura jamaicensis). Binary builds are listed below. Feedback is very welcome.

Note: This release introduces a backwards-incompatible change to the on-disk storage format. We suggest you use the EXPORT DATABASE command with the old version followed by IMPORT DATABASE with the new version to migrate your data. See the documentation for details.

Also note: Due to changes in the internal storage (#1530), databases created with this release wil require somewhat more disk space. This is transient as we are working hard to finalise the on-disk storage format.

Major changes:

Engine

#1666: External merge sort, #1580: Parallel scan of ordered result and #1561: Rework physical ORDER BY
#1520 & #1574: Window function computation parallelism
#1540: Add table functions that take a subquery parameter
#1533: Using vectors, instead of column chunks as lists
#1530: Store null values separate from main data in a Validity Segment

SQL

#1568: Positional Reference Operator #1 etc.
#1671: QUANTILE variants and #1685: Temporal quantiles
#1695: New Timestamp Types TIMESTAMP_NS, TIMESTAMP_MS and TIMESTAMP_NS
#1647: Add support for UTC offset timestamp parsing to regular timestamp conversion
#1659: Add support for USING keyword in DELETE statement
#1638, #1663, #1621 & #1484: Many changes arount ARRAY syntax
#1610: Add support for CURRVAL
#1544: Add SKIP as an option to READ_CSV and COPY

APIs

#1525: Add loadable extensions support
#1711: Parallel Arrow Scans
#1569: Map-style UDFs for Python API
#1534: Extensible Replacement Scans & Automatic Pandas Scans and #1487: Automatically use parquet or CSV scan when using a table name that ends in .parquet or .csv
#1649: Add a QueryRelation object that can be used to convert a query directly into a relation object, #1665: Adding from_query to python api
#1550: Shell: Add support for Ctrl + arrow keys to linenoise, and make Ctrl+C terminate the current query instead of the process
#1514: Using ALTREP to speed up string column transfer to R
#1502: R: implementation of Rstudio connection-contract tab