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mysql_fdw.c
4903 lines (4259 loc) · 143 KB
/
mysql_fdw.c
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/*-------------------------------------------------------------------------
*
* mysql_fdw.c
* Foreign-data wrapper for remote MySQL servers
*
* Portions Copyright (c) 2012-2014, PostgreSQL Global Development Group
* Portions Copyright (c) 2004-2024, EnterpriseDB Corporation.
*
* IDENTIFICATION
* mysql_fdw.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
/*
* Must be included before mysql.h as it has some conflicting definitions like
* list_length, etc.
*/
#include "mysql_fdw.h"
#include <dlfcn.h>
#include <errmsg.h>
#include <mysql.h>
#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>
#include "access/htup_details.h"
#include "access/sysattr.h"
#include "access/reloptions.h"
#include "access/table.h"
#include "commands/defrem.h"
#include "commands/explain.h"
#include "catalog/heap.h"
#include "catalog/pg_type.h"
#include "foreign/fdwapi.h"
#include "miscadmin.h"
#include "mysql_pushability.h"
#include "mysql_query.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "nodes/nodes.h"
#if PG_VERSION_NUM >= 140000
#include "optimizer/appendinfo.h"
#endif
#include "optimizer/pathnode.h"
#include "optimizer/paths.h"
#include "optimizer/planmain.h"
#include "optimizer/optimizer.h"
#include "optimizer/restrictinfo.h"
#include "optimizer/tlist.h"
#include "parser/parsetree.h"
#if PG_VERSION_NUM >= 160000
#include "parser/parse_relation.h"
#endif
#include "storage/ipc.h"
#include "utils/builtins.h"
#include "utils/datum.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/regproc.h"
#include "utils/selfuncs.h"
#include "utils/syscache.h"
#include "utils/typcache.h"
/* Declarations for dynamic loading */
PG_MODULE_MAGIC;
int ((mysql_options) (MYSQL *mysql, enum mysql_option option,
const void *arg));
int ((mysql_stmt_prepare) (MYSQL_STMT *stmt, const char *query,
unsigned long length));
int ((mysql_stmt_execute) (MYSQL_STMT *stmt));
int ((mysql_stmt_fetch) (MYSQL_STMT *stmt));
int ((mysql_query) (MYSQL *mysql, const char *q));
bool ((mysql_stmt_attr_set) (MYSQL_STMT *stmt,
enum enum_stmt_attr_type attr_type,
const void *attr));
bool ((mysql_stmt_close) (MYSQL_STMT *stmt));
bool ((mysql_stmt_reset) (MYSQL_STMT *stmt));
bool ((mysql_free_result) (MYSQL_RES *result));
bool ((mysql_stmt_bind_param) (MYSQL_STMT *stmt, MYSQL_BIND *bnd));
bool ((mysql_stmt_bind_result) (MYSQL_STMT *stmt, MYSQL_BIND *bnd));
MYSQL_STMT *((mysql_stmt_init) (MYSQL *mysql));
MYSQL_RES *((mysql_stmt_result_metadata) (MYSQL_STMT *stmt));
int ((mysql_stmt_store_result) (MYSQL_STMT *stmt));
MYSQL_ROW((mysql_fetch_row) (MYSQL_RES *result));
MYSQL_FIELD *((mysql_fetch_field) (MYSQL_RES *result));
MYSQL_FIELD *((mysql_fetch_fields) (MYSQL_RES *result));
const char *((mysql_error) (MYSQL *mysql));
void ((mysql_close) (MYSQL *sock));
MYSQL_RES *((mysql_store_result) (MYSQL *mysql));
MYSQL *((mysql_init) (MYSQL *mysql));
bool ((mysql_ssl_set) (MYSQL *mysql, const char *key, const char *cert,
const char *ca, const char *capath,
const char *cipher));
MYSQL *((mysql_real_connect) (MYSQL *mysql, const char *host, const char *user,
const char *passwd, const char *db,
unsigned int port, const char *unix_socket,
unsigned long clientflag));
const char *((mysql_get_host_info) (MYSQL *mysql));
const char *((mysql_get_server_info) (MYSQL *mysql));
int ((mysql_get_proto_info) (MYSQL *mysql));
unsigned int ((mysql_stmt_errno) (MYSQL_STMT *stmt));
unsigned int ((mysql_errno) (MYSQL *mysql));
unsigned int ((mysql_num_fields) (MYSQL_RES *result));
unsigned int ((mysql_num_rows) (MYSQL_RES *result));
#define DEFAULTE_NUM_ROWS 1000
/*
* In PG 9.5.1 the number will be 90501,
* our version is 2.9.1 so number will be 20901
*/
#define CODE_VERSION 20901
/*
* The number of rows in a foreign relation are estimated to be so less that
* an in-memory sort on those many rows wouldn't cost noticeably higher than
* the underlying scan. Hence for now, cost sorts same as underlying scans.
*/
#define DEFAULT_MYSQL_SORT_MULTIPLIER 1
/*
* Indexes of FDW-private information stored in fdw_private lists.
*
* These items are indexed with the enum mysqlFdwScanPrivateIndex, so an item
* can be fetched with list_nth(). For example, to get the SELECT statement:
* sql = strVal(list_nth(fdw_private, mysqlFdwScanPrivateSelectSql));
*/
enum mysqlFdwScanPrivateIndex
{
/* SQL statement to execute remotely (as a String node) */
mysqlFdwScanPrivateSelectSql,
/* Integer list of attribute numbers retrieved by the SELECT */
mysqlFdwScanPrivateRetrievedAttrs,
/*
* String describing join i.e. names of relations being joined and types
* of join, added when the scan is join
*/
mysqlFdwScanPrivateRelations,
/*
* List of Var node lists for constructing the whole-row references of
* base relations involved in pushed down join.
*/
mysqlFdwPrivateWholeRowLists,
/*
* Targetlist representing the result fetched from the foreign server if
* whole-row references are involved.
*/
mysqlFdwPrivateScanTList
};
/*
* This enum describes what's kept in the fdw_private list for a ForeignPath.
* We store:
*
* 1) Boolean flag showing if the remote query has the final sort
* 2) Boolean flag showing if the remote query has the LIMIT clause
*/
enum FdwPathPrivateIndex
{
/* has-final-sort flag (as an integer Value node) */
FdwPathPrivateHasFinalSort,
/* has-limit flag (as an integer Value node) */
FdwPathPrivateHasLimit
};
extern PGDLLEXPORT void _PG_init(void);
extern Datum mysql_fdw_handler(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(mysql_fdw_handler);
PG_FUNCTION_INFO_V1(mysql_fdw_version);
PG_FUNCTION_INFO_V1(mysql_display_pushdown_list);
/*
* FDW callback routines
*/
static void mysqlExplainForeignScan(ForeignScanState *node, ExplainState *es);
static void mysqlBeginForeignScan(ForeignScanState *node, int eflags);
static TupleTableSlot *mysqlIterateForeignScan(ForeignScanState *node);
static void mysqlReScanForeignScan(ForeignScanState *node);
static void mysqlEndForeignScan(ForeignScanState *node);
static List *mysqlPlanForeignModify(PlannerInfo *root, ModifyTable *plan,
Index resultRelation, int subplan_index);
static void mysqlBeginForeignModify(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo,
List *fdw_private, int subplan_index,
int eflags);
static TupleTableSlot *mysqlExecForeignInsert(EState *estate,
ResultRelInfo *resultRelInfo,
TupleTableSlot *slot,
TupleTableSlot *planSlot);
#if PG_VERSION_NUM >= 140000
static void mysqlAddForeignUpdateTargets(PlannerInfo *root,
Index rtindex,
RangeTblEntry *target_rte,
Relation target_relation);
#else
static void mysqlAddForeignUpdateTargets(Query *parsetree,
RangeTblEntry *target_rte,
Relation target_relation);
#endif
static TupleTableSlot *mysqlExecForeignUpdate(EState *estate,
ResultRelInfo *resultRelInfo,
TupleTableSlot *slot,
TupleTableSlot *planSlot);
static TupleTableSlot *mysqlExecForeignDelete(EState *estate,
ResultRelInfo *resultRelInfo,
TupleTableSlot *slot,
TupleTableSlot *planSlot);
static void mysqlEndForeignModify(EState *estate,
ResultRelInfo *resultRelInfo);
static void mysqlGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel,
Oid foreigntableid);
static void mysqlGetForeignPaths(PlannerInfo *root, RelOptInfo *baserel,
Oid foreigntableid);
static bool mysqlAnalyzeForeignTable(Relation relation,
AcquireSampleRowsFunc *func,
BlockNumber *totalpages);
static ForeignScan *mysqlGetForeignPlan(PlannerInfo *root,
RelOptInfo *foreignrel,
Oid foreigntableid,
ForeignPath *best_path, List *tlist,
List *scan_clauses, Plan *outer_plan);
static void mysqlEstimateCosts(PlannerInfo *root, RelOptInfo *baserel,
Cost *startup_cost, Cost *total_cost,
Oid foreigntableid);
static void mysqlGetForeignJoinPaths(PlannerInfo *root,
RelOptInfo *joinrel,
RelOptInfo *outerrel,
RelOptInfo *innerrel,
JoinType jointype,
JoinPathExtraData *extra);
static bool mysqlRecheckForeignScan(ForeignScanState *node,
TupleTableSlot *slot);
static void mysqlGetForeignUpperPaths(PlannerInfo *root,
UpperRelationKind stage,
RelOptInfo *input_rel,
RelOptInfo *output_rel,
void *extra);
static List *mysqlImportForeignSchema(ImportForeignSchemaStmt *stmt,
Oid serverOid);
static void mysqlBeginForeignInsert(ModifyTableState *mtstate,
ResultRelInfo *resultRelInfo);
static void mysqlEndForeignInsert(EState *estate,
ResultRelInfo *resultRelInfo);
#if PG_VERSION_NUM >= 140000
static void mysqlExecForeignTruncate(List *rels,
DropBehavior behavior,
bool restart_seqs);
#endif
/*
* Helper functions
*/
bool mysql_load_library(void);
static void mysql_fdw_exit(int code, Datum arg);
static bool mysql_is_column_unique(Oid foreigntableid);
static void prepare_query_params(PlanState *node,
List *fdw_exprs,
int numParams,
FmgrInfo **param_flinfo,
List **param_exprs,
const char ***param_values,
Oid **param_types);
static void process_query_params(ExprContext *econtext,
FmgrInfo *param_flinfo,
List *param_exprs,
const char **param_values,
MYSQL_BIND **mysql_bind_buf,
Oid *param_types);
static void bind_stmt_params_and_exec(ForeignScanState *node);
static bool mysql_foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel,
JoinType jointype, RelOptInfo *outerrel,
RelOptInfo *innerrel,
JoinPathExtraData *extra);
static List *mysql_adjust_whole_row_ref(PlannerInfo *root,
List *scan_var_list,
List **whole_row_lists,
Bitmapset *relids);
static List *mysql_build_scan_list_for_baserel(Oid relid, Index varno,
Bitmapset *attrs_used,
List **retrieved_attrs);
static void mysql_build_whole_row_constr_info(MySQLFdwExecState *festate,
TupleDesc tupdesc,
Bitmapset *relids,
int max_relid,
List *whole_row_lists,
List *scan_tlist,
List *fdw_scan_tlist);
static HeapTuple mysql_get_tuple_with_whole_row(MySQLFdwExecState *festate,
Datum *values, bool *nulls);
static HeapTuple mysql_form_whole_row(MySQLWRState *wr_state, Datum *values,
bool *nulls);
static bool mysql_foreign_grouping_ok(PlannerInfo *root,
RelOptInfo *grouped_rel,
Node *havingQual);
static void mysql_add_foreign_grouping_paths(PlannerInfo *root,
RelOptInfo *input_rel,
RelOptInfo *grouped_rel,
GroupPathExtraData *extra);
static List *mysql_get_useful_ecs_for_relation(PlannerInfo *root,
RelOptInfo *rel);
static List *mysql_get_useful_pathkeys_for_relation(PlannerInfo *root,
RelOptInfo *rel);
static void mysql_add_paths_with_pathkeys(PlannerInfo *root,
RelOptInfo *rel,
Path *epq_path,
Cost base_startup_cost,
Cost base_total_cost);
static void mysql_add_foreign_ordered_paths(PlannerInfo *root,
RelOptInfo *input_rel,
RelOptInfo *ordered_rel);
static void mysql_add_foreign_final_paths(PlannerInfo *root,
RelOptInfo *input_rel,
RelOptInfo *final_rel,
FinalPathExtraData *extra);
#if PG_VERSION_NUM >= 160000
static TargetEntry *mysql_tlist_member_match_var(Var *var, List *targetlist);
static List *mysql_varlist_append_unique_var(List *varlist, Var *var);
#endif
void *mysql_dll_handle = NULL;
static int wait_timeout = WAIT_TIMEOUT;
static int interactive_timeout = INTERACTIVE_TIMEOUT;
static void mysql_error_print(MYSQL *conn);
static void mysql_stmt_error_print(MySQLFdwExecState *festate,
const char *msg);
static List *getUpdateTargetAttrs(PlannerInfo *root, RangeTblEntry *rte);
#if PG_VERSION_NUM >= 140000
static char *mysql_remove_quotes(char *s1);
#endif
/*
* mysql_load_library function dynamically load the mysql's library
* libmysqlclient.so. The only reason to load the library using dlopen
* is that, mysql and postgres both have function with same name like
* "list_delete", "list_delete" and "list_free" which cause compiler
* error "duplicate function name" and erroneously linking with a function.
* This port of the code is used to avoid the compiler error.
*
* #define list_delete mysql_list_delete
* #include <mysql.h>
* #undef list_delete
*
* But system crashed on function mysql_stmt_close function because
* mysql_stmt_close internally calling "list_delete" function which
* wrongly binds to postgres' "list_delete" function.
*
* The dlopen function provides a parameter "RTLD_DEEPBIND" which
* solved the binding issue.
*
* RTLD_DEEPBIND:
* Place the lookup scope of the symbols in this library ahead of the
* global scope. This means that a self-contained library will use its
* own symbols in preference to global symbols with the same name contained
* in libraries that have already been loaded.
*/
bool
mysql_load_library(void)
{
#if defined(__APPLE__) || defined(__FreeBSD__)
/*
* Mac OS/BSD does not support RTLD_DEEPBIND, but it still works without
* the RTLD_DEEPBIND
*/
mysql_dll_handle = dlopen(_MYSQL_LIBNAME, RTLD_LAZY);
#else
mysql_dll_handle = dlopen(_MYSQL_LIBNAME, RTLD_LAZY | RTLD_DEEPBIND);
#endif
if (mysql_dll_handle == NULL)
return false;
_mysql_stmt_bind_param = dlsym(mysql_dll_handle, "mysql_stmt_bind_param");
_mysql_stmt_bind_result = dlsym(mysql_dll_handle, "mysql_stmt_bind_result");
_mysql_stmt_init = dlsym(mysql_dll_handle, "mysql_stmt_init");
_mysql_stmt_prepare = dlsym(mysql_dll_handle, "mysql_stmt_prepare");
_mysql_stmt_execute = dlsym(mysql_dll_handle, "mysql_stmt_execute");
_mysql_stmt_fetch = dlsym(mysql_dll_handle, "mysql_stmt_fetch");
_mysql_query = dlsym(mysql_dll_handle, "mysql_query");
_mysql_stmt_result_metadata = dlsym(mysql_dll_handle, "mysql_stmt_result_metadata");
_mysql_stmt_store_result = dlsym(mysql_dll_handle, "mysql_stmt_store_result");
_mysql_fetch_row = dlsym(mysql_dll_handle, "mysql_fetch_row");
_mysql_fetch_field = dlsym(mysql_dll_handle, "mysql_fetch_field");
_mysql_fetch_fields = dlsym(mysql_dll_handle, "mysql_fetch_fields");
_mysql_stmt_close = dlsym(mysql_dll_handle, "mysql_stmt_close");
_mysql_stmt_reset = dlsym(mysql_dll_handle, "mysql_stmt_reset");
_mysql_free_result = dlsym(mysql_dll_handle, "mysql_free_result");
_mysql_error = dlsym(mysql_dll_handle, "mysql_error");
_mysql_options = dlsym(mysql_dll_handle, "mysql_options");
_mysql_ssl_set = dlsym(mysql_dll_handle, "mysql_ssl_set");
_mysql_real_connect = dlsym(mysql_dll_handle, "mysql_real_connect");
_mysql_close = dlsym(mysql_dll_handle, "mysql_close");
_mysql_init = dlsym(mysql_dll_handle, "mysql_init");
_mysql_stmt_attr_set = dlsym(mysql_dll_handle, "mysql_stmt_attr_set");
_mysql_store_result = dlsym(mysql_dll_handle, "mysql_store_result");
_mysql_stmt_errno = dlsym(mysql_dll_handle, "mysql_stmt_errno");
_mysql_errno = dlsym(mysql_dll_handle, "mysql_errno");
_mysql_num_fields = dlsym(mysql_dll_handle, "mysql_num_fields");
_mysql_num_rows = dlsym(mysql_dll_handle, "mysql_num_rows");
_mysql_get_host_info = dlsym(mysql_dll_handle, "mysql_get_host_info");
_mysql_get_server_info = dlsym(mysql_dll_handle, "mysql_get_server_info");
_mysql_get_proto_info = dlsym(mysql_dll_handle, "mysql_get_proto_info");
if (_mysql_stmt_bind_param == NULL ||
_mysql_stmt_bind_result == NULL ||
_mysql_stmt_init == NULL ||
_mysql_stmt_prepare == NULL ||
_mysql_stmt_execute == NULL ||
_mysql_stmt_fetch == NULL ||
_mysql_query == NULL ||
_mysql_stmt_result_metadata == NULL ||
_mysql_stmt_store_result == NULL ||
_mysql_fetch_row == NULL ||
_mysql_fetch_field == NULL ||
_mysql_fetch_fields == NULL ||
_mysql_stmt_close == NULL ||
_mysql_stmt_reset == NULL ||
_mysql_free_result == NULL ||
_mysql_error == NULL ||
_mysql_options == NULL ||
_mysql_ssl_set == NULL ||
_mysql_real_connect == NULL ||
_mysql_close == NULL ||
_mysql_init == NULL ||
_mysql_stmt_attr_set == NULL ||
_mysql_store_result == NULL ||
_mysql_stmt_errno == NULL ||
_mysql_errno == NULL ||
_mysql_num_fields == NULL ||
_mysql_num_rows == NULL ||
_mysql_get_host_info == NULL ||
_mysql_get_server_info == NULL ||
_mysql_get_proto_info == NULL)
return false;
return true;
}
/*
* Library load-time initialization, sets on_proc_exit() callback for
* backend shutdown.
*/
void
_PG_init(void)
{
if (!mysql_load_library())
ereport(ERROR,
(errcode(ERRCODE_FDW_UNABLE_TO_CREATE_EXECUTION),
errmsg("failed to load the mysql query: \n%s", dlerror()),
errhint("Export LD_LIBRARY_PATH to locate the library.")));
DefineCustomIntVariable("mysql_fdw.wait_timeout",
"Server-side wait_timeout",
"Set the maximum wait_timeout"
"use to set the MySQL session timeout",
&wait_timeout,
WAIT_TIMEOUT,
0,
INT_MAX,
PGC_USERSET,
0,
NULL,
NULL,
NULL);
DefineCustomIntVariable("mysql_fdw.interactive_timeout",
"Server-side interactive timeout",
"Set the maximum interactive timeout"
"use to set the MySQL session timeout",
&interactive_timeout,
INTERACTIVE_TIMEOUT,
0,
INT_MAX,
PGC_USERSET,
0,
NULL,
NULL,
NULL);
on_proc_exit(&mysql_fdw_exit, PointerGetDatum(NULL));
}
/*
* mysql_fdw_exit
* Exit callback function.
*/
static void
mysql_fdw_exit(int code, Datum arg)
{
mysql_cleanup_connection();
}
/*
* Foreign-data wrapper handler function: return
* a struct with pointers to my callback routines.
*/
Datum
mysql_fdw_handler(PG_FUNCTION_ARGS)
{
FdwRoutine *fdwroutine = makeNode(FdwRoutine);
/* Functions for scanning foreign tables */
fdwroutine->GetForeignRelSize = mysqlGetForeignRelSize;
fdwroutine->GetForeignPaths = mysqlGetForeignPaths;
fdwroutine->GetForeignPlan = mysqlGetForeignPlan;
fdwroutine->BeginForeignScan = mysqlBeginForeignScan;
fdwroutine->IterateForeignScan = mysqlIterateForeignScan;
fdwroutine->ReScanForeignScan = mysqlReScanForeignScan;
fdwroutine->EndForeignScan = mysqlEndForeignScan;
/* Functions for updating foreign tables */
fdwroutine->AddForeignUpdateTargets = mysqlAddForeignUpdateTargets;
fdwroutine->PlanForeignModify = mysqlPlanForeignModify;
fdwroutine->BeginForeignModify = mysqlBeginForeignModify;
fdwroutine->ExecForeignInsert = mysqlExecForeignInsert;
fdwroutine->ExecForeignUpdate = mysqlExecForeignUpdate;
fdwroutine->ExecForeignDelete = mysqlExecForeignDelete;
fdwroutine->EndForeignModify = mysqlEndForeignModify;
/* Function for EvalPlanQual rechecks */
fdwroutine->RecheckForeignScan = mysqlRecheckForeignScan;
/* Support functions for EXPLAIN */
fdwroutine->ExplainForeignScan = mysqlExplainForeignScan;
/* Support functions for ANALYZE */
fdwroutine->AnalyzeForeignTable = mysqlAnalyzeForeignTable;
/* Support functions for IMPORT FOREIGN SCHEMA */
fdwroutine->ImportForeignSchema = mysqlImportForeignSchema;
/* Partition routing and/or COPY from */
fdwroutine->BeginForeignInsert = mysqlBeginForeignInsert;
fdwroutine->EndForeignInsert = mysqlEndForeignInsert;
/* Support functions for join push-down */
fdwroutine->GetForeignJoinPaths = mysqlGetForeignJoinPaths;
/* Support functions for upper relation push-down */
fdwroutine->GetForeignUpperPaths = mysqlGetForeignUpperPaths;
#if PG_VERSION_NUM >= 140000
/* Support function for TRUNCATE */
fdwroutine->ExecForeignTruncate = mysqlExecForeignTruncate;
#endif
PG_RETURN_POINTER(fdwroutine);
}
/*
* mysqlBeginForeignScan
* Initiate access to the database
*/
static void
mysqlBeginForeignScan(ForeignScanState *node, int eflags)
{
TupleTableSlot *tupleSlot = node->ss.ss_ScanTupleSlot;
TupleDesc tupleDescriptor = tupleSlot->tts_tupleDescriptor;
MYSQL *conn;
RangeTblEntry *rte;
MySQLFdwExecState *festate;
EState *estate = node->ss.ps.state;
ForeignScan *fsplan = (ForeignScan *) node->ss.ps.plan;
mysql_opt *options;
ListCell *lc;
int atindex = 0;
unsigned long type = (unsigned long) CURSOR_TYPE_READ_ONLY;
Oid userid;
ForeignServer *server;
UserMapping *user;
ForeignTable *table;
char timeout[255];
int numParams;
int rtindex;
List *fdw_private = fsplan->fdw_private;
char sql_mode[255];
/*
* We'll save private state in node->fdw_state.
*/
festate = (MySQLFdwExecState *) palloc(sizeof(MySQLFdwExecState));
node->fdw_state = (void *) festate;
/*
* If whole-row references are involved in pushed down join extract the
* information required to construct those.
*/
if (list_length(fdw_private) >= mysqlFdwPrivateScanTList)
{
List *whole_row_lists = list_nth(fdw_private,
mysqlFdwPrivateWholeRowLists);
List *scan_tlist = list_nth(fdw_private,
mysqlFdwPrivateScanTList);
TupleDesc scan_tupdesc = ExecTypeFromTL(scan_tlist);
mysql_build_whole_row_constr_info(festate, tupleDescriptor,
fsplan->fs_relids,
list_length(node->ss.ps.state->es_range_table),
whole_row_lists, scan_tlist,
fsplan->fdw_scan_tlist);
/* Change tuple descriptor to match the result from foreign server. */
tupleDescriptor = scan_tupdesc;
}
/*
* Identify which user to do the remote access as. This should match what
* ExecCheckRTEPerms() does. In case of a join use the lowest-numbered
* member RTE as a representative; we would get the same result from any.
*/
if (fsplan->scan.scanrelid > 0)
rtindex = fsplan->scan.scanrelid;
else
#if PG_VERSION_NUM >= 160000
rtindex = bms_next_member(fsplan->fs_base_relids, -1);
#else
rtindex = bms_next_member(fsplan->fs_relids, -1);
#endif
#if PG_VERSION_NUM >= 160000
rte = exec_rt_fetch(rtindex, estate);
userid = fsplan->checkAsUser ? fsplan->checkAsUser : GetUserId();
#else
rte = rt_fetch(rtindex, estate->es_range_table);
userid = rte->checkAsUser ? rte->checkAsUser : GetUserId();
#endif
/* Get info about foreign table. */
table = GetForeignTable(rte->relid);
server = GetForeignServer(table->serverid);
user = GetUserMapping(userid, server->serverid);
/* Fetch the options */
options = mysql_get_options(rte->relid, true);
/*
* Get the already connected connection, otherwise connect and get the
* connection handle.
*/
conn = mysql_get_connection(server, user, options);
/* Stash away the state info we have already */
festate->query = strVal(list_nth(fsplan->fdw_private,
mysqlFdwScanPrivateSelectSql));
festate->retrieved_attrs = list_nth(fsplan->fdw_private,
mysqlFdwScanPrivateRetrievedAttrs);
festate->conn = conn;
festate->query_executed = false;
festate->has_var_size_col = false;
festate->attinmeta = TupleDescGetAttInMetadata(tupleDescriptor);
festate->temp_cxt = AllocSetContextCreate(estate->es_query_cxt,
"mysql_fdw temporary data",
ALLOCSET_DEFAULT_SIZES);
if (wait_timeout > 0)
{
/* Set the session timeout in seconds */
sprintf(timeout, "SET wait_timeout = %d", wait_timeout);
mysql_query(festate->conn, timeout);
}
if (interactive_timeout > 0)
{
/* Set the session timeout in seconds */
sprintf(timeout, "SET interactive_timeout = %d", interactive_timeout);
mysql_query(festate->conn, timeout);
}
snprintf(sql_mode, sizeof(sql_mode), "SET sql_mode = '%s'",
options->sql_mode);
if (mysql_query(festate->conn, sql_mode) != 0)
mysql_error_print(festate->conn);
/* Initialize the MySQL statement */
festate->stmt = mysql_stmt_init(festate->conn);
if (festate->stmt == NULL)
ereport(ERROR,
(errcode(ERRCODE_FDW_UNABLE_TO_CREATE_EXECUTION),
errmsg("failed to initialize the mysql query: \n%s",
mysql_error(festate->conn))));
/* Prepare MySQL statement */
if (mysql_stmt_prepare(festate->stmt, festate->query,
strlen(festate->query)) != 0)
mysql_stmt_error_print(festate, "failed to prepare the MySQL query");
/* Prepare for output conversion of parameters used in remote query. */
numParams = list_length(fsplan->fdw_exprs);
festate->numParams = numParams;
if (numParams > 0)
prepare_query_params((PlanState *) node,
fsplan->fdw_exprs,
numParams,
&festate->param_flinfo,
&festate->param_exprs,
&festate->param_values,
&festate->param_types);
/* int column_count = mysql_num_fields(festate->meta); */
/* Set the statement as cursor type */
mysql_stmt_attr_set(festate->stmt, STMT_ATTR_CURSOR_TYPE, (void *) &type);
/* Set the pre-fetch rows */
mysql_stmt_attr_set(festate->stmt, STMT_ATTR_PREFETCH_ROWS,
(void *) &options->fetch_size);
festate->table = (mysql_table *) palloc0(sizeof(mysql_table));
festate->table->column = (mysql_column *) palloc0(sizeof(mysql_column) * tupleDescriptor->natts);
festate->table->mysql_bind = (MYSQL_BIND *) palloc0(sizeof(MYSQL_BIND) * tupleDescriptor->natts);
festate->table->mysql_res = mysql_stmt_result_metadata(festate->stmt);
if (NULL == festate->table->mysql_res)
ereport(ERROR,
(errcode(ERRCODE_FDW_UNABLE_TO_CREATE_EXECUTION),
errmsg("failed to retrieve query result set metadata: \n%s",
mysql_error(festate->conn))));
festate->table->mysql_fields = mysql_fetch_fields(festate->table->mysql_res);
foreach(lc, festate->retrieved_attrs)
{
int attnum = lfirst_int(lc) - 1;
Oid pgtype = TupleDescAttr(tupleDescriptor, attnum)->atttypid;
int32 pgtypmod = TupleDescAttr(tupleDescriptor, attnum)->atttypmod;
if (TupleDescAttr(tupleDescriptor, attnum)->attisdropped)
continue;
if (pgtype == TEXTOID)
festate->has_var_size_col = true;
festate->table->column[atindex].mysql_bind = &festate->table->mysql_bind[atindex];
mysql_bind_result(pgtype, pgtypmod,
&festate->table->mysql_fields[atindex],
&festate->table->column[atindex]);
atindex++;
}
/*
* Set STMT_ATTR_UPDATE_MAX_LENGTH so that mysql_stmt_store_result() can
* update metadata MYSQL_FIELD->max_length value, this will be useful to
* determine var length column size.
*/
mysql_stmt_attr_set(festate->stmt, STMT_ATTR_UPDATE_MAX_LENGTH,
&festate->has_var_size_col);
/* Bind the results pointers for the prepare statements */
if (mysql_stmt_bind_result(festate->stmt, festate->table->mysql_bind) != 0)
mysql_stmt_error_print(festate, "failed to bind the MySQL query");
}
/*
* mysqlIterateForeignScan
* Iterate and get the rows one by one from MySQL and placed in tuple
* slot
*/
static TupleTableSlot *
mysqlIterateForeignScan(ForeignScanState *node)
{
MySQLFdwExecState *festate = (MySQLFdwExecState *) node->fdw_state;
TupleTableSlot *tupleSlot = node->ss.ss_ScanTupleSlot;
int attid;
ListCell *lc;
int rc = 0;
Datum *dvalues;
bool *nulls;
int natts;
AttInMetadata *attinmeta = festate->attinmeta;
HeapTuple tup;
int i;
ForeignScan *fsplan = (ForeignScan *) node->ss.ps.plan;
List *fdw_private = fsplan->fdw_private;
natts = attinmeta->tupdesc->natts;
dvalues = palloc0(natts * sizeof(Datum));
nulls = palloc(natts * sizeof(bool));
/* Initialize to nulls for any columns not present in result */
memset(nulls, true, natts * sizeof(bool));
ExecClearTuple(tupleSlot);
/*
* If this is the first call after Begin or ReScan, we need to bind the
* params and execute the query.
*/
if (!festate->query_executed)
bind_stmt_params_and_exec(node);
attid = 0;
rc = mysql_stmt_fetch(festate->stmt);
if (rc == 0)
{
foreach(lc, festate->retrieved_attrs)
{
int attnum = lfirst_int(lc) - 1;
Oid pgtype = TupleDescAttr(attinmeta->tupdesc, attnum)->atttypid;
int32 pgtypmod = TupleDescAttr(attinmeta->tupdesc, attnum)->atttypmod;
nulls[attnum] = festate->table->column[attid].is_null;
if (!festate->table->column[attid].is_null)
dvalues[attnum] = mysql_convert_to_pg(pgtype, pgtypmod,
&festate->table->column[attid]);
attid++;
}
ExecClearTuple(tupleSlot);
if (list_length(fdw_private) >= mysqlFdwPrivateScanTList)
{
/* Construct tuple with whole-row references. */
tup = mysql_get_tuple_with_whole_row(festate, dvalues, nulls);
}
else
{
/* Form the Tuple using Datums */
tup = heap_form_tuple(attinmeta->tupdesc, dvalues, nulls);
}
if (tup)
ExecStoreHeapTuple(tup, tupleSlot, false);
else
mysql_stmt_close(festate->stmt);
/*
* Release locally palloc'd space and values of pass-by-reference
* datums, as well.
*/
for (i = 0; i < natts; i++)
{
if (dvalues[i] && !TupleDescAttr(attinmeta->tupdesc, i)->attbyval)
pfree(DatumGetPointer(dvalues[i]));
}
pfree(dvalues);
pfree(nulls);
}
else if (rc == 1)
{
/*
* Error occurred. Error code and message can be obtained by calling
* mysql_stmt_errno() and mysql_stmt_error().
*/
}
else if (rc == MYSQL_NO_DATA)
{
/*
* No more rows/data exists
*/
}
else if (rc == MYSQL_DATA_TRUNCATED)
{
/* Data truncation occurred */
/*
* MYSQL_DATA_TRUNCATED is returned when truncation reporting is
* enabled. To determine which column values were truncated when this
* value is returned, check the error members of the MYSQL_BIND
* structures used for fetching values. Truncation reporting is
* enabled by default, but can be controlled by calling
* mysql_options() with the MYSQL_REPORT_DATA_TRUNCATION option.
*/
}
return tupleSlot;
}
/*
* mysqlExplainForeignScan
* Produce extra output for EXPLAIN
*/
static void
mysqlExplainForeignScan(ForeignScanState *node, ExplainState *es)
{
MySQLFdwExecState *festate = (MySQLFdwExecState *) node->fdw_state;
RangeTblEntry *rte;
ForeignScan *fsplan = (ForeignScan *) node->ss.ps.plan;
int rtindex;
EState *estate = node->ss.ps.state;
List *fdw_private = fsplan->fdw_private;
if (fsplan->scan.scanrelid > 0)
rtindex = fsplan->scan.scanrelid;
else
#if PG_VERSION_NUM >= 160000
rtindex = bms_next_member(fsplan->fs_base_relids, -1);
#else
rtindex = bms_next_member(fsplan->fs_relids, -1);
#endif
rte = rt_fetch(rtindex, estate->es_range_table);
if (list_length(fdw_private) > mysqlFdwScanPrivateRelations)
{
char *relations = strVal(list_nth(fdw_private,
mysqlFdwScanPrivateRelations));
ExplainPropertyText("Relations", relations, es);
}
/* Give some possibly useful info about startup costs */
if (es->costs)
{
mysql_opt *options = mysql_get_options(rte->relid, true);
if (strcmp(options->svr_address, "127.0.0.1") == 0 ||
strcmp(options->svr_address, "localhost") == 0)
ExplainPropertyInteger("Local server startup cost", NULL, 10, es);
else
ExplainPropertyInteger("Remote server startup cost", NULL, 25, es);
}
/* Show the remote query in verbose mode */
if (es->verbose)
ExplainPropertyText("Remote query", festate->query, es);
}
/*
* mysqlEndForeignScan
* Finish scanning foreign table and dispose objects used for this scan
*/
static void
mysqlEndForeignScan(ForeignScanState *node)
{
MySQLFdwExecState *festate = (MySQLFdwExecState *) node->fdw_state;
if (festate->table && festate->table->mysql_res)
{
mysql_free_result(festate->table->mysql_res);
festate->table->mysql_res = NULL;
}
if (festate->stmt)
{
mysql_stmt_close(festate->stmt);
festate->stmt = NULL;
}
}
/*
* mysqlReScanForeignScan
* Rescan table, possibly with new parameters
*/
static void
mysqlReScanForeignScan(ForeignScanState *node)
{
MySQLFdwExecState *festate = (MySQLFdwExecState *) node->fdw_state;
/*
* Set the query_executed flag to false so that the query will be executed
* in mysqlIterateForeignScan().
*/
festate->query_executed = false;
}
/*
* mysqlGetForeignRelSize
* Create a FdwPlan for a scan on the foreign table
*/
static void
mysqlGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel,
Oid foreigntableid)
{
double rows = 0;
double filtered = 0;
MYSQL *conn;
MYSQL_ROW row;
Bitmapset *attrs_used = NULL;
mysql_opt *options;
Oid userid = GetUserId();
ForeignServer *server;
UserMapping *user;
ForeignTable *table;
MySQLFdwRelationInfo *fpinfo;
ListCell *lc;
RangeTblEntry *rte = planner_rt_fetch(baserel->relid, root);