mirror of
https://github.com/postgres/postgres.git
synced 2025-06-08 22:02:03 +03:00
The initial implementation of this feature was really unsupportable, because it's relying on the physical size of an on-disk file to carry the relation's populated/unpopulated state, which is at least a modularity violation and could have serious long-term consequences. We could say that an unlogged matview goes to empty on crash, but not everybody likes that definition, so let's just remove the feature for 9.3. We can add it back when we have a less klugy implementation. I left the grammar and tab-completion support for CREATE UNLOGGED MATERIALIZED VIEW in place, since it's harmless and allows delivering a more specific error message about the unsupported feature. I'm committing this separately to ease identification of what should be reverted when/if we are able to re-enable the feature.
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 kwlookup.c turn keywords into specific tokens keywords.c table of standard keywords (passed to kwlookup.c) 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_func.c handle functions, table.column and column identifiers 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)