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We now create contype='n' pg_constraint rows for not-null constraints on user tables. Only one such constraint is allowed for a column. We propagate these constraints to other tables during operations such as adding inheritance relationships, creating and attaching partitions and creating tables LIKE other tables. These related constraints mostly follow the well-known rules of conislocal and coninhcount that we have for CHECK constraints, with some adaptations: for example, as opposed to CHECK constraints, we don't match not-null ones by name when descending a hierarchy to alter or remove it, instead matching by the name of the column that they apply to. This means we don't require the constraint names to be identical across a hierarchy. The inheritance status of these constraints can be controlled: now we can be sure that if a parent table has one, then all children will have it as well. They can optionally be marked NO INHERIT, and then children are free not to have one. (There's currently no support for altering a NO INHERIT constraint into inheriting down the hierarchy, but that's a desirable future feature.) This also opens the door for having these constraints be marked NOT VALID, as well as allowing UNIQUE+NOT NULL to be used for functional dependency determination, as envisioned by commit |
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| .. | ||
| .gitignore | ||
| analyze.c | ||
| check_keywords.pl | ||
| gram.y | ||
| gramparse.h | ||
| Makefile | ||
| meson.build | ||
| parse_agg.c | ||
| parse_clause.c | ||
| parse_coerce.c | ||
| parse_collate.c | ||
| parse_cte.c | ||
| parse_enr.c | ||
| parse_expr.c | ||
| parse_func.c | ||
| parse_jsontable.c | ||
| parse_merge.c | ||
| parse_node.c | ||
| parse_oper.c | ||
| parse_param.c | ||
| parse_relation.c | ||
| parse_target.c | ||
| parse_type.c | ||
| parse_utilcmd.c | ||
| parser.c | ||
| README | ||
| scan.l | ||
| scansup.c | ||
src/backend/parser/README Parser ====== This directory does more than tokenize and parse SQL queries. It also creates Query structures for the various complex queries that are passed to the optimizer and then executor. parser.c things start here scan.l break query into tokens scansup.c handle escapes in input strings gram.y parse the tokens and produce a "raw" parse tree analyze.c top level of parse analysis for optimizable queries parse_agg.c handle aggregates, like SUM(col1), AVG(col2), ... parse_clause.c handle clauses like WHERE, ORDER BY, GROUP BY, ... parse_coerce.c handle coercing expressions to different data types parse_collate.c assign collation information in completed expressions parse_cte.c handle Common Table Expressions (WITH clauses) parse_expr.c handle expressions like col, col + 3, x = 3 or x = 4 parse_enr.c handle ephemeral named rels (trigger transition tables, ...) parse_func.c handle functions, table.column and column identifiers parse_merge.c handle MERGE parse_node.c create nodes for various structures parse_oper.c handle operators in expressions parse_param.c handle Params (for the cases used in the core backend) parse_relation.c support routines for tables and column handling parse_target.c handle the result list of the query parse_type.c support routines for data type handling parse_utilcmd.c parse analysis for utility commands (done at execution time) See also src/common/keywords.c, which contains the table of standard keywords and the keyword lookup function. We separated that out because various frontend code wants to use it too.