replace_property_refs() called expression_tree_mutator() with the root
of the expression tree as the input node. But
expression_tree_mutator() does not call the mutator function on the
root node, so the root node remains unchanged. If the root node is a
property reference or a lateral reference -- the two node kinds that
replace_property_refs_mutator() rewrites -- it is returned unchanged.
Modules after the rewriter do not know about property reference nodes,
resulting in "ERROR: unrecognized node type: 63". Since varlevelsup
of lateral references is not incremented, they are not resolved
correctly in the planner, leading to many different symptoms. Fix
this by calling replace_property_refs_mutator() directly from
replace_property_refs(), similar to how other mutator functions do.
The only case when a property reference or a lateral reference can be
the root of a GRAPH_TABLE expression tree is when it is a bare
property reference or a bare lateral reference in the WHERE clause.
The COLUMNS clause is passed to replace_property_refs() as a
targetlist. Every other expression has at least one expression node
covering the property reference or a lateral reference in the
expression tree. That explains why this bug was not seen so far.
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reported-by: Noah Misch <noah@leadboat.com>
Discussion: https://www.postgresql.org/message-id/flat/20260630173053.51.noahmisch%40microsoft.com
A view definition with GRAPH_TABLE depends upon the property graph it
references as well as the properties and labels referenced in it. We
recorded the dependency on the property graph, but did not record
dependency on labels and properties. This allowed properties or
labels referenced by a view to be dropped, resulting in a cache lookup
error when such a view was accessed. Fix this bug by handling
GraphPropertyRef and GraphLabelRef in find_expr_references_walker().
The dependency on the data type of property does not need to be
recorded separately as it is recorded indirectly via a dependency on
the property graph property itself.
Note that a property or a label associated with individual elements
can still be dropped as long as there are other elements that are
associated with that property or label, since they do not lead to
dropping the property or the label from the property graph altogether.
Reported-by: Man Zeng <zengman@halodbtech.com>
Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Junwang Zhao <zhjwpku@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/tencent_43D9888041FA4FDE498C7BF1%40qq.com
When rewriting a GRAPH_TABLE into a subquery,
replace_property_refs_mutator() bumps levelsup of lateral references
by one so that they reference outside the subquery. This works for
path patterns that result in only one path query. Patterns that
produce multiple path queries are rewritten as a UNION of path
queries. Since every path query becomes a subquery of the UNION
statement, the levelsup of lateral references in those path queries
need an additional bump. This adjustment was missing resulting in the
lateral references being interpreted as references in the UNION query
itself. This caused different symptoms like a crash in
create_lateral_join_info() or error "plan should not reference
subplan's variable". The symptoms varied depending on the number of
RangeTblEntries in the UNION statement.
This commit adds the missing adjustment.
Author: Ayush Tiwari <ayushtiwari.slg01@gmail.com>
Author: Satya Narlapuram <satyanarlapuram@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CAHg%2BQDfnLzsgjaQ_CiKSpP4JH3MKOiwoawEcCzXa9uYr45yiWw%40mail.gmail.com
expression_tree_mutator_impl() did not handle T_GraphPattern,
T_GraphElementPattern, and T_GraphPropertyRef. The corresponding
expression_tree_walker_impl() already handles all three node types.
This causes an "unrecognized node type" error whenever a GRAPH_TABLE
appeared in an expression tree.
While at it, also update raw_expression_tree_walker() and
expression_tree_walker() to handle missing nodes that may appear in
GraphPattern expression trees. When raw_expression_tree_walker() is
called, GraphElementPattern::labelexpr contains ColumnRefs instead of
GraphLabelRefs. Hence those are not handled in
raw_expression_tree_walker().
Author: Satyanarayana Narlapuram <satyanarlapuram@gmail.com>
Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CAHg%2BQDc97WFTSkXg%3Dg_ZAH8GnY2gJrvq72cs%2BYjqEAuZgXnkAQ%40mail.gmail.com
Expressions in GRAPH_TABLE COLUMNS list may have lateral references.
get_rule_expr() requires lateral namespaces to deparse such
references. get_from_clause_item() does not pass them when processing
the expressions in COLUMNS list causing ERROR "bogus varlevelsup: 0
offset 0". Fix get_from_clause_item() to pass input deparse_context
containing lateral namespaces to get_rule_expr() instead of the dummy
context.
Author: Satyanarayana Narlapuram <satyanarlapuram@gmail.com>
Reviewed-by: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/CAHg%2BQDcLVa2iBnggkHxY4itZbXtDMfsYHEjnCUYe9hNbnxDi-w%40mail.gmail.com
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
