New Features

Views

Views are virtual tables defined by a SELECT statement. They do not persist data on disk. Instead, the underlying query is executed as a subquery each time the view is referenced.

Complex calculations and logic can be captured in a view, and shared across database users.

CREATE VIEW latest_trades AS
SELECT
  symbol,
  side,
  last(price) AS price,
  last(timestamp) AS ts
FROM trades
GROUP BY symbol, side;

Views can be queried just like tables, while always reflecting the latest data from their source tables.

Parameterisation

Views can be parameterised:

CREATE VIEW filtered_trades AS (
  DECLARE 
      OVERRIDABLE @min_price := 100
  SELECT ts, symbol, price 
  FROM trades 
  WHERE price >= @min_price
);

This view contains the @min_price parameter, with a default value. Additionally, its tagged as OVERRIDABLE. This means that the user reading from the View can alter this parameter:

DECLARE 
    @min_price := 500 
SELECT * FROM filtered_trades

Within a View, DECLARE variables are constant unless explicitly declared to be OVERRIDABLE. This allows you to create Views with pre-set filters, limiting which rows the end user has access to:

CREATE VIEW last_24h_trades AS (
   DECLARE 
       @min_ts := dateadd('d', -1, now())
   SELECT * FROM trades 
   WHERE timestamp >= @min_ts
)

The end user cannot widen this lower time bounds parameter.

Please see the docs for more information.

PIVOT

This release introduces the new PIVOT keyword.

PIVOT is a specialised form of GROUP BY that transforms rows into columns, helping you move from a narrow schema to a wide one in a single query.

A traditional aggregation might look like this (try on demo!):

SELECT side, symbol, last(price) AS price
FROM trades_latest_1d
WHERE symbol IN ('BTC-USD', 'ETH-USD')
ORDER BY side, symbol;

Resulting in a narrow result set:

| side | symbol | price | | ---- | ------- | ------- | | buy | BTC-USD | 91128.4 | | buy | ETH-USD | 3111.53 | | sell | BTC-USD | 91128.3 | | sell | ETH-USD | 3111.48 |

With PIVOT, the same aggregate can be computed and output with a column generated for each pivot key combination. In this case, the pivoting key is symbol, and the aggregate value is last(price).

trades_latest_1d
PIVOT (
  last(price)
  FOR symbol IN ('BTC-USD', 'ETH-USD')
  GROUP BY side
) ORDER BY side;

| side | BTC-USD | ETH-USD | | ---- | ------- | ------- | | buy | 91484.5 | 3129.76 | | sell | 91484.4 | 3129.47 |

This makes it much easier to work with dashboarding and data analysis tools, where column-per-symbol is a natural analysis and charting format.

Dynamic PIVOT keys

PIVOT can generate columns based on keys generated by a query. For example:

trades_latest_1d
PIVOT (
  last(price)
  FOR symbol IN (SELECT DISTINCT symbol FROM trades_latest_1d)
  GROUP BY side
) ORDER BY side;

| side | SOL-BTC | ETH-USDC | BTC-USD | DOT-USD | DOGE-USDT | ADA-USD | ... | | ---- | --------- | -------- | ------- | ------- | --------- | ------- | --- | | buy | 0.0015273 | 4235.24 | 91576.3 | 2.132 | 0.22609 | 0.4029 | ... | | sell | 0.0015257 | 4235.95 | 91572.9 | 2.131 | 0.22603 | 0.4025 | ... |

Please see the docs for more information.

Window joins (beta)

QuestDB now supports WINDOW JOIN, a new join syntax designed specifically for time-based analytics.

WINDOW JOIN allows each row from a primary table to be joined with a time window of rows from another table, with aggregations computed over the matching rows. This makes short-horizon analytics—such as correlating trades with nearby market prices—both expressive and efficient.

SELECT
  t.*,
  avg(p.bid) AS avg_bid,
  avg(p.ask) AS avg_ask
FROM trades t
WINDOW JOIN prices p
  ON p.sym = t.sym
  RANGE BETWEEN 1 second PRECEDING
        AND 1 second FOLLOWING
  INCLUDE PREVAILING;

In this example, each row from trades is joined with all rows from prices that share the same symbol and fall within the [-1s, +1s] interval (inclusive). Aggregations are then calculated over the joined rows.

This syntax avoids complex subqueries and makes time-windowed joins explicit, readable, and performant, with SIMD acceleration employed for the most common aggregate functions.

Please see the docs for more information.

AI-assisted workflows in the Web Console (beta)

The QuestDB Web Console now includes LLM-powered assistance, available on an opt-in basis using your own API key.

Once enabled, the console can:

• Auto-describe table schemas and column semantics
• Annotate sample rows with plain-language context
• Walk through query execution plans, highlighting joins, filters, and index usage

This makes it easier to understand both what a query does and how it executes—directly where you write SQL.

Performance

• JIT-compiled filters have undergone an optimisation pass, and will now execute up to 2x faster.
• Queries with GROUP BY, ORDER BY and LIMIT can now be executed in parallel, with execution times up to 10x faster.
• SELECT min(timestamp), max(timestamp) FROM table will now execute in O(1) time (instantly), when timestamp is the designated timestamp.
• Querying external parquet files with read_parquet('data.parquet') will now use projection pushdown, signficantly reducing disk and memory usage, and speeding up execution times by as much as 100x.
• Parquet exporting has been sped up by reducing the number of intermediate commits applied during the copy process.

Changelist

• fix(sql): segfault when using touch() on a table with a new empty column by @nwoolmer in https://github.com/questdb/questdb/pull/6561
• feat(sql): window join by @puzpuzpuz in https://github.com/questdb/questdb/pull/6292
• fix(pgwire): add support for SHOW default_transaction_read_only by @nwoolmer in https://github.com/questdb/questdb/pull/6562
• fix(core): fix incorrect designated timestamp column displayed by tables() after column type changes by @glasstiger in https://github.com/questdb/questdb/pull/6570
• fix(sql): support copies of very wide tables and result sets by @nwoolmer in https://github.com/questdb/questdb/pull/6525
• fix(sql): fix false timestamp ordering error with nested SAMPLE BY and ORDER BY by @bluestreak01 in https://github.com/questdb/questdb/pull/6572
• perf(sql): avoid expensive row counting in EXPLAIN query with LIMIT by @mtopolnik in https://github.com/questdb/questdb/pull/6540
• feat(sql): align glob() function with DuckDB glob syntax by @kafka1991 in https://github.com/questdb/questdb/pull/6552
• perf(sql): speed up JIT-compiled filters by reordering predicates and short-circuiting them by @puzpuzpuz in https://github.com/questdb/questdb/pull/6568
• feat(core): release disk space faster on table drop by @ideoma in https://github.com/questdb/questdb/pull/6555
• perf(sql): speed up row counting in filter queries by @puzpuzpuz in https://github.com/questdb/questdb/pull/6580
• feat(pgwire): support VARCHAR[] bind variables for symbol/varchar/str IN expressions by @kafka1991 in https://github.com/questdb/questdb/pull/6574
• feat(sql): add column projection pushdown for read_parquet() by @kafka1991 in https://github.com/questdb/questdb/pull/6551
• perf(sql): parallel ORDER BY long_column LIMIT N for high-cardinality GROUP BY by @puzpuzpuz in https://github.com/questdb/questdb/pull/6582
• fix(sql): fix EXPLAIN UPDATE resulting in error by @bluestreak01 in https://github.com/questdb/questdb/pull/6588
• fix(sql): handle quoted column names with dots in JOIN metadata by @jerrinot in https://github.com/questdb/questdb/pull/6590
• feat(sql): add rowCount, txn and timestamp columns to tables() by @bluestreak01 in https://github.com/questdb/questdb/pull/6581
• perf(sql): speed up min/max aggregates on designated timestamp by @puzpuzpuz in https://github.com/questdb/questdb/pull/6593
• fix(sql): inefficient commit batching during parquet exports by @nwoolmer in https://github.com/questdb/questdb/pull/6596
• fix(conf): auto-detect native libs in jlink runtime by @jerrinot in https://github.com/questdb/questdb/pull/6493
• fix(core): prevent rounding overflow from being ignored during decimal divisions by @RaphDal in https://github.com/questdb/questdb/pull/6598
• feat(sql): support PIVOT keyword for rotating rows to columns by @nwoolmer in https://github.com/questdb/questdb/pull/5313
• fix(pgwire): allow large varchar column regardless of send buffer size by @jerrinot in https://github.com/questdb/questdb/pull/6603
• chore(conf): claude.md to steer agents by @jerrinot in https://github.com/questdb/questdb/pull/6607
• feat(core): views by @glasstiger in https://github.com/questdb/questdb/pull/5720
• fix(sql): collect dependent columns during top-down projection propagation by @kafka1991 in https://github.com/questdb/questdb/pull/6600
• fix(web-console): add polyfill for crypto.randomUUID to be used in insecure contexts by @emrberk in https://github.com/questdb/ui/pull/508
• fix(web-console): handle running new queries when there is an operaton in progress by @emrberk in https://github.com/questdb/ui/pull/511
• feat(web-console): ai assistant with chat window by @emrberk in https://github.com/questdb/ui/pull/507
• feat(web-console): views support by @jerrinot and @emrberk in https://github.com/questdb/ui/pull/512
• fix(web-console): fix XSS vulnerability by @bluestreak01 in https://github.com/questdb/ui/pull/519
• fix(web-console): declare statements breaking query key parsing by @emrberk in https://github.com/questdb/ui/pull/522

Full Changelog: https://github.com/questdb/questdb/compare/9.2.3...9.3.0