The CircuitBreaker was introduced as means of preventing a
`StackOverflowException` during the build of the AST by the parser.
The ANTLR4 grammar causes a weird behaviour for a Parser Listener.
The `enterEveryRule()` method is often called with a different parsing
context than the respective `exitEveryRule()`. This makes it difficult
to keep track of the tree's depth, and a custom Map was used as an
attempt of matching the contextes as they are encounter during `enter`
and during `exit` of the rules.
This approach had 2 important drawbacks:
1. It's hard to maintain this custom Map as the grammar changes.
2. The CircuitBreaker could often lead to false positives which caused
valid queries to return an Exception and prevent them from executing.
So, this removes completely the CircuitBreaker which is replaced be
a simple handling of the `StackOverflowException`
Fixes: #41471
To avoid having to specify each spec by hand (which can miss specs to be
added), the test infrastructure now performs classpath discovery so that
each spec added, is automatically considered.
Relates #40358
For cases where fields can have multi values, allow the behavior to be
customized through a dedicated configuration field.
By default this will be enabled on the drivers so that existing datasets
work instead of throwing an exception.
For regular SQL usage, the behavior is false so that the user is aware
of the underlying data.
Fix#39700
* SYS COLUMNS will skip UNSUPPORTED field types in ODBC and JDBC, as well.
NESTED and OBJECT types were already skipped in ODBC mode, now they are
skipped in JDBC mode, as well.
Introduce client-side sorting of groups based on aggregate
functions. To allow this, the Analyzer has been extended to push down
to underlying Aggregate, aggregate function and the Querier has been
extended to identify the case and consume the results in order and sort
them based on the given columns.
The underlying QueryContainer has been slightly modified to allow a view
of the underlying values being extracted as the columns used for sorting
might not be requested by the user.
The PR also adds minor tweaks, mainly related to tree output.
Close#35118
Currently aggregate functions can operate only directly on fields.
They cannot be used on top of scalar functions as painless scripting
is currently not supported.
FIRST and LAST can be used with one argument and work similarly to MIN
and MAX but they are implemented using a Top Hits aggregation and
therefore can also operate on keyword fields. When a second argument is
provided then they return the first/last value of the first arg when its
values are ordered ascending/descending (respectively) by the values of
the second argument. Currently because of the usage of a Top Hits
aggregation FIRST and LAST cannot be used in the HAVING clause of a
GROUP BY query to filter on the results of the aggregation.
Closes: #35639
* Added Limitations page
* Made the aggregations page follow the common template for functions
* Modified all tables to have the first row's cells content centered
* Polishing in other various sections
Marios Trivyzas
James Rodewig
Costin Leau
Andrei Stefan