Function exec_parse_message

src/backend/tcop/postgres.c:2063–2358

* exec_parse_message * * Execute a "Parse" protocol message. */

 * Execute a "Parse" protocol message.
 */
static void
exec_parse_message(const char *query_string,	/* string to execute */
				   const char *stmt_name,	/* name for prepared stmt */
				   Oid *paramTypes, /* parameter types */
				   int numParams)	/* number of parameters */
{
	MemoryContext unnamed_stmt_context = NULL;
	MemoryContext oldcontext;
	List	   *parsetree_list;
	RawStmt    *raw_parse_tree;
	List	   *querytree_list;
	CachedPlanSource *psrc;
	bool		is_named;
	bool		save_log_statement_stats = log_statement_stats;
	char		msec_str[32];
	NodeTag		sourceTag = T_Query;

	/*
	 * Report query to various monitoring facilities.
	 */
	debug_query_string = query_string;

	pgstat_report_activity(STATE_RUNNING, query_string);

	set_ps_display("PARSE");

	if (save_log_statement_stats)
		ResetUsage();

	ereport(DEBUG2,
			(errmsg_internal("parse %s: %s",
							 *stmt_name ? stmt_name : "<unnamed>",
							 query_string)));

	/*
	 * Start up a transaction command so we can run parse analysis etc. (Note
	 * that this will normally change current memory context.) Nothing happens
	 * if we are already in one.  This also arms the statement timeout if
	 * necessary.
	 */
	start_xact_command();

	/*
	 * Switch to appropriate context for constructing parsetrees.
	 *
	 * We have two strategies depending on whether the prepared statement is
	 * named or not.  For a named prepared statement, we do parsing in
	 * MessageContext and copy the finished trees into the prepared
	 * statement's plancache entry; then the reset of MessageContext releases
	 * temporary space used by parsing and rewriting. For an unnamed prepared
	 * statement, we assume the statement isn't going to hang around long, so
	 * getting rid of temp space quickly is probably not worth the costs of
	 * copying parse trees.  So in this case, we create the plancache entry's
	 * query_context here, and do all the parsing work therein.
	 */
	is_named = (stmt_name[0] != '\0');
	if (is_named)
	{