GRAPH_TABLE clause is converted into a rangetable entry, which is
ignored by assign_query_collations(). Hence we assign collations
while transforming its parts. But expressions in COLUMNS clause
missed that treatment, so fix that.
While at it, also add comments about collation assignment to the parts
of GRAPH_TABLE clause, and also fix a small grammar issue.
Reported-by: Satyanarayana Narlapuram <satyanarlapuram@gmail.com>
Author: Satyanarayana Narlapuram <satyanarlapuram@gmail.com>
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://www.postgresql.org/message-id/CAHg+QDc4aaiufYSgrwMMPMMRTPtQ66SghcrPFbWJFZMqNaG+BA@mail.gmail.com
When converting the WHERE clause in an element pattern,
generate_query_for_graph_path() calls replace_property_refs() to
replace the property references in it. Only the current graph element
pattern is passed as the context for replacement. If there are
references to variables from other element patterns, it causes a
segmentation fault (an assertion failure in an Assert enabled build)
since it does not find path_element object corresponding to those
variables.
We do not support forward and backward variable references within a
graph table clause. Hence prohibit all the cross references.
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reported-by: Man Zeng <zengman@halodbtech.com>
Reviewed-by: Henson Choi <assam258@gmail.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://www.postgresql.org/message-id/CAExHW5u6AoDfNg4%3DR5eVJn_bJn%3DC%3DwVPrto02P_06fxy39fniA%40mail.gmail.com
When a ColumnRef can be resolved as a graph table property reference
and a lateral table column reference prefer the graph table property
reference since element pattern variables in the GRAPH_TABLE clause
form the innermost namespace.
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Henson Choi <assam258@gmail.com>
Discussion: https://www.postgresql.org/message-id/CAExHW5u6AoDfNg4%3DR5eVJn_bJn%3DC%3DwVPrto02P_06fxy39fniA%40mail.gmail.com
Adding an implicit empty vertex pattern when a path pattern starts or
ends with an edge pattern or when two consecutive edge patterns appear
in the pattern is not supported right now. Prohibit such path
patterns.
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reported-by: Alexander Lakhin <exclusion@gmail.com>
Reviewed-by: Henson Choi <assam258@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/72a23702-6d96-4103-a54b-057c2352e885%2540eisentraut.org
Implementation of SQL property graph queries, according to SQL/PGQ
standard (ISO/IEC 9075-16:2023).
This adds:
- GRAPH_TABLE table function for graph pattern matching
- DDL commands CREATE/ALTER/DROP PROPERTY GRAPH
- several new system catalogs and information schema views
- psql \dG command
- pg_get_propgraphdef() function for pg_dump and psql
A property graph is a relation with a new relkind RELKIND_PROPGRAPH.
It acts like a view in many ways. It is rewritten to a standard
relational query in the rewriter. Access privileges act similar to a
security invoker view. (The security definer variant is not currently
implemented.)
Starting documentation can be found in doc/src/sgml/ddl.sgml and
doc/src/sgml/queries.sgml.
Author: Peter Eisentraut <peter@eisentraut.org>
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Reviewed-by: Ajay Pal <ajay.pal.k@gmail.com>
Reviewed-by: Henson Choi <assam258@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/a855795d-e697-4fa5-8698-d20122126567@eisentraut.org
