继续分析：
setup_schema();
展开：
实质就是创建info_schema。
cmd 是：
"/home/pgsql/project/bin/postgres" --single -F -O -c search_path=pg_catalog -c exit_on_error=true -j template1 >/dev/null
infor_schem_file是：/home/pgsql/project/share/information_schema.sql
/*
* load info schema and populate from features file
*/
static void
setup_schema(void)
{
PG_CMD_DECL;
char **line;
char **lines; fputs(_("creating information schema ... "), stdout);
fflush(stdout); lines = readfile(info_schema_file); ///fprintf(stderr,"\n====================info_schema_file is: %s\n", info_schema_file); /*
* We use -j here to avoid backslashing stuff in information_schema.sql
*/
snprintf(cmd, sizeof(cmd),
"\"%s\" %s -j template1 >%s",
backend_exec, backend_options,
DEVNULL); ///fprintf(stderr,"\n=====================cmd is: %s \n",cmd); PG_CMD_OPEN; for (line = lines; *line != NULL; line++)
{
PG_CMD_PUTS(*line);
free(*line);
} free(lines); PG_CMD_CLOSE; snprintf(cmd, sizeof(cmd),
"\"%s\" %s template1 >%s",
backend_exec, backend_options,
DEVNULL); PG_CMD_OPEN; PG_CMD_PRINTF1("UPDATE information_schema.sql_implementation_info "
" SET character_value = '%s' "
" WHERE implementation_info_name = 'DBMS VERSION';\n",
infoversion); PG_CMD_PRINTF1("COPY information_schema.sql_features "
" (feature_id, feature_name, sub_feature_id, "
" sub_feature_name, is_supported, comments) "
" FROM E'%s';\n",
escape_quotes(features_file)); PG_CMD_CLOSE; check_ok();
}