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oracle_fdw.c
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/*-------------------------------------------------------------------------
*
* oracle_fdw.c
* PostgreSQL-related functions for Oracle foreign data wrapper.
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "fmgr.h"
#include "access/htup_details.h"
#include "access/reloptions.h"
#include "access/sysattr.h"
#include "access/xact.h"
#include "catalog/indexing.h"
#include "catalog/pg_attribute.h"
#include "catalog/pg_cast.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_foreign_data_wrapper.h"
#include "catalog/pg_foreign_server.h"
#include "catalog/pg_foreign_table.h"
#include "catalog/pg_namespace.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_user_mapping.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "commands/explain.h"
#include "commands/vacuum.h"
#include "foreign/fdwapi.h"
#include "foreign/foreign.h"
/* for "hash_bytes_extended" or "hash_bytes" */
#if PG_VERSION_NUM >= 130000
#include "common/hashfn.h"
#elif PG_VERSION_NUM >= 120000
#include "utils/hashutils.h"
#else
#include "access/hash.h"
#endif /* PG_VERSION_NUM */
#if PG_VERSION_NUM < 110000
#define hash_bytes_extended(k, keylen, seed) \
DatumGetInt32(hash_any((k), (keylen)))
#elif PG_VERSION_NUM < 130000
#define hash_bytes_extended(k, keylen, seed) \
DatumGetInt64(hash_any_extended((k), (keylen), (seed)))
#endif /* PG_VERSION_NUM */
#include "libpq/pqsignal.h"
#include "mb/pg_wchar.h"
#include "miscadmin.h"
#include "nodes/makefuncs.h"
#include "nodes/nodeFuncs.h"
#include "nodes/pg_list.h"
#include "optimizer/cost.h"
#if PG_VERSION_NUM >= 140000
#include "optimizer/appendinfo.h"
#endif /* PG_VERSION_NUM */
#include "optimizer/pathnode.h"
#if PG_VERSION_NUM >= 130000
#include "optimizer/inherit.h"
#include "optimizer/paths.h"
#endif /* PG_VERSION_NUM */
#include "optimizer/planmain.h"
#include "optimizer/restrictinfo.h"
#include "optimizer/tlist.h"
#include "parser/parse_relation.h"
#include "parser/parsetree.h"
#include "pgtime.h"
#include "port.h"
#include "storage/ipc.h"
#include "storage/lock.h"
#include "tcop/tcopprot.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "utils/catcache.h"
#include "utils/date.h"
#include "utils/datetime.h"
#include "utils/elog.h"
#include "utils/fmgroids.h"
#include "utils/formatting.h"
#include "utils/guc.h"
#include "utils/lsyscache.h"
#include "utils/memutils.h"
#include "utils/rel.h"
#include "utils/resowner.h"
#include "utils/timestamp.h"
#include "utils/snapmgr.h"
#include "utils/syscache.h"
#include "utils/timestamp.h"
#if PG_VERSION_NUM < 120000
#include "nodes/relation.h"
#include "optimizer/var.h"
#include "utils/tqual.h"
#else
#include "nodes/pathnodes.h"
#include "optimizer/optimizer.h"
#include "access/heapam.h"
#endif
#include <string.h>
#include <stdlib.h>
#include "oracle_fdw.h"
/* defined in backend/commands/analyze.c */
#ifndef WIDTH_THRESHOLD
#define WIDTH_THRESHOLD 1024
#endif /* WIDTH_THRESHOLD */
#if PG_VERSION_NUM >= 90500
#define IMPORT_API
/* array_create_iterator has a new signature from 9.5 on */
#define array_create_iterator(arr, slice_ndim) array_create_iterator(arr, slice_ndim, NULL)
#else
#undef IMPORT_API
#endif /* PG_VERSION_NUM */
#if PG_VERSION_NUM >= 90600
#define JOIN_API
/* the useful macro IS_SIMPLE_REL is defined in v10, backport */
#ifndef IS_SIMPLE_REL
#define IS_SIMPLE_REL(rel) \
((rel)->reloptkind == RELOPT_BASEREL || \
(rel)->reloptkind == RELOPT_OTHER_MEMBER_REL)
#endif
/* GetConfigOptionByName has a new signature from 9.6 on */
#define GetConfigOptionByName(name, varname) GetConfigOptionByName(name, varname, false)
#else
#undef JOIN_API
#endif /* PG_VERSION_NUM */
#if PG_VERSION_NUM < 110000
/* backport macro from V11 */
#define TupleDescAttr(tupdesc, i) ((tupdesc)->attrs[(i)])
#endif /* PG_VERSION_NUM */
/* list API has changed in v13 */
#if PG_VERSION_NUM < 130000
#define list_next(l, e) lnext((e))
#define do_each_cell(cell, list, element) for_each_cell(cell, (element))
#else
#define list_next(l, e) lnext((l), (e))
#define do_each_cell(cell, list, element) for_each_cell(cell, (list), (element))
#endif /* PG_VERSION_NUM */
/* "table_open" was "heap_open" before v12 */
#if PG_VERSION_NUM < 120000
#define table_open(x, y) heap_open(x, y)
#define table_close(x, y) heap_close(x, y)
#endif /* PG_VERSION_NUM */
PG_MODULE_MAGIC;
/*
* "true" if Oracle data have been modified in the current transaction.
*/
static bool dml_in_transaction = false;
/*
* PostGIS geometry type, set in initializePostGIS().
*/
static Oid GEOMETRYOID = InvalidOid;
static bool geometry_is_setup = false;
/*
* Describes the valid options for objects that use this wrapper.
*/
struct OracleFdwOption
{
const char *optname;
Oid optcontext; /* Oid of catalog in which option may appear */
bool optrequired;
};
#define OPT_NLS_LANG "nls_lang"
#define OPT_DBSERVER "dbserver"
#define OPT_ISOLATION_LEVEL "isolation_level"
#define OPT_NCHAR "nchar"
#define OPT_USER "user"
#define OPT_PASSWORD "password"
#define OPT_DBLINK "dblink"
#define OPT_SCHEMA "schema"
#define OPT_TABLE "table"
#define OPT_MAX_LONG "max_long"
#define OPT_READONLY "readonly"
#define OPT_KEY "key"
#define OPT_STRIP_ZEROS "strip_zeros"
#define OPT_SAMPLE "sample_percent"
#define OPT_PREFETCH "prefetch"
#define OPT_LOB_PREFETCH "lob_prefetch"
#define OPT_SET_TIMEZONE "set_timezone"
/* these options are only for IMPORT FOREIGN SCHEMA */
#define OPT_CASE "case"
#define OPT_COLLATION "collation"
#define OPT_SKIP_TABLES "skip_tables"
#define OPT_SKIP_VIEWS "skip_views"
#define OPT_SKIP_MATVIEWS "skip_matviews"
#define DEFAULT_ISOLATION_LEVEL ORA_TRANS_SERIALIZABLE
#define DEFAULT_MAX_LONG 32767
#define DEFAULT_PREFETCH 50
#define MAXIMUM_PREFETCH 10240
#define DEFAULT_LOB_PREFETCH 1048576
/*
* Options for case folding for names in IMPORT FOREIGN TABLE.
*/
typedef enum { CASE_KEEP, CASE_LOWER, CASE_SMART } fold_t;
/*
* Valid options for oracle_fdw.
*/
static struct OracleFdwOption valid_options[] = {
{OPT_NLS_LANG, ForeignDataWrapperRelationId, false},
{OPT_DBSERVER, ForeignServerRelationId, true},
{OPT_ISOLATION_LEVEL, ForeignServerRelationId, false},
{OPT_NCHAR, ForeignServerRelationId, false},
{OPT_USER, UserMappingRelationId, true},
{OPT_PASSWORD, UserMappingRelationId, true},
{OPT_DBLINK, ForeignTableRelationId, false},
{OPT_SCHEMA, ForeignTableRelationId, false},
{OPT_TABLE, ForeignTableRelationId, true},
{OPT_MAX_LONG, ForeignTableRelationId, false},
{OPT_READONLY, ForeignTableRelationId, false},
{OPT_SAMPLE, ForeignTableRelationId, false},
{OPT_PREFETCH, ForeignTableRelationId, false},
{OPT_LOB_PREFETCH, ForeignTableRelationId, false},
{OPT_KEY, AttributeRelationId, false},
{OPT_STRIP_ZEROS, AttributeRelationId, false},
{OPT_SET_TIMEZONE, ForeignServerRelationId, false}
};
#define option_count (sizeof(valid_options)/sizeof(struct OracleFdwOption))
/*
* Array to hold the type output functions during table modification.
* It is ok to hold this cache in a static variable because there cannot
* be more than one foreign table modified at the same time.
*/
static regproc *output_funcs;
/*
* FDW-specific information for RelOptInfo.fdw_private and ForeignScanState.fdw_state.
* The same structure is used to hold information for query planning and execution.
* The structure is initialized during query planning and passed on to the execution
* step serialized as a List (see serializePlanData and deserializePlanData).
* For DML statements, the scan stage and the modify stage both hold an
* OracleFdwState, and the latter is initialized by copying the former (see copyPlanData).
*/
struct OracleFdwState {
char *dbserver; /* Oracle connect string */
oraIsoLevel isolation_level; /* Transaction Isolation Level */
char *user; /* Oracle username */
char *password; /* Oracle password */
char *nls_lang; /* Oracle locale information */
char *timezone; /* session time zone */
bool have_nchar; /* needs support for national character conversion */
oracleSession *session; /* encapsulates the active Oracle session */
char *query; /* query we issue against Oracle */
List *params; /* list of parameters needed for the query */
struct paramDesc *paramList; /* description of parameters needed for the query */
struct oraTable *oraTable; /* description of the remote Oracle table */
Cost startup_cost; /* cost estimate, only needed for planning */
Cost total_cost; /* cost estimate, only needed for planning */
unsigned int prefetch; /* number of rows to prefetch */
unsigned int lob_prefetch; /* number of LOB bytes to prefetch */
unsigned long rowcount; /* rows already read from Oracle */
int columnindex; /* currently processed column for error context */
MemoryContext temp_cxt; /* short-lived memory for data modification */
char *order_clause; /* for ORDER BY pushdown */
List *usable_pathkeys; /* for ORDER BY pushdown */
char *where_clause; /* deparsed where clause */
/*
* Restriction clauses, divided into safe and unsafe to pushdown subsets.
*
* For a base foreign relation this is a list of clauses along-with
* RestrictInfo wrapper. Keeping RestrictInfo wrapper helps while dividing
* scan_clauses in oracleGetForeignPlan into safe and unsafe subsets.
* Also it helps in estimating costs since RestrictInfo caches the
* selectivity and qual cost for the clause in it.
*
* For a join relation, however, they are part of otherclause list
* obtained from extract_actual_join_clauses, which strips RestrictInfo
* construct. So, for a join relation they are list of bare clauses.
*/
List *remote_conds; /* can be pushed down to remote server */
List *local_conds; /* cannot be pushed down to remote server */
/* Join information */
RelOptInfo *outerrel;
RelOptInfo *innerrel;
JoinType jointype;
List *joinclauses;
};
/*
* SQL functions
*/
extern PGDLLEXPORT Datum oracle_fdw_handler(PG_FUNCTION_ARGS);
extern PGDLLEXPORT Datum oracle_fdw_validator(PG_FUNCTION_ARGS);
extern PGDLLEXPORT Datum oracle_close_connections(PG_FUNCTION_ARGS);
extern PGDLLEXPORT Datum oracle_diag(PG_FUNCTION_ARGS);
extern PGDLLEXPORT Datum oracle_execute(PG_FUNCTION_ARGS);
PG_FUNCTION_INFO_V1(oracle_fdw_handler);
PG_FUNCTION_INFO_V1(oracle_fdw_validator);
PG_FUNCTION_INFO_V1(oracle_close_connections);
PG_FUNCTION_INFO_V1(oracle_diag);
PG_FUNCTION_INFO_V1(oracle_execute);
/*
* on-load initializer
*/
extern PGDLLEXPORT void _PG_init(void);
/*
* FDW callback routines
*/
static void oracleGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid);
static void oracleGetForeignPaths(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid);
#ifdef JOIN_API
static void oracleGetForeignJoinPaths(PlannerInfo *root, RelOptInfo *joinrel, RelOptInfo *outerrel, RelOptInfo *innerrel, JoinType jointype, JoinPathExtraData *extra);
#endif /* JOIN_API */
static ForeignScan *oracleGetForeignPlan(PlannerInfo *root, RelOptInfo *foreignrel, Oid foreigntableid, ForeignPath *best_path, List *tlist, List *scan_clauses
#if PG_VERSION_NUM >= 90500
, Plan *outer_plan
#endif /* PG_VERSION_NUM */
);
static bool oracleAnalyzeForeignTable(Relation relation, AcquireSampleRowsFunc *func, BlockNumber *totalpages);
static void oracleExplainForeignScan(ForeignScanState *node, ExplainState *es);
static void oracleBeginForeignScan(ForeignScanState *node, int eflags);
static TupleTableSlot *oracleIterateForeignScan(ForeignScanState *node);
static void oracleEndForeignScan(ForeignScanState *node);
static void oracleReScanForeignScan(ForeignScanState *node);
#if PG_VERSION_NUM < 140000
static void oracleAddForeignUpdateTargets(Query *parsetree, RangeTblEntry *target_rte, Relation target_relation);
#else
static void oracleAddForeignUpdateTargets(PlannerInfo *root, Index rtindex, RangeTblEntry *target_rte, Relation target_relation);
#endif
static List *oraclePlanForeignModify(PlannerInfo *root, ModifyTable *plan, Index resultRelation, int subplan_index);
static void oracleBeginForeignModify(ModifyTableState *mtstate, ResultRelInfo *rinfo, List *fdw_private, int subplan_index, int eflags);
#if PG_VERSION_NUM >= 110000
static void oracleBeginForeignInsert(ModifyTableState *mtstate, ResultRelInfo *rinfo);
static void oracleEndForeignInsert(EState *estate, ResultRelInfo *rinfo);
#endif /*PG_VERSION_NUM */
static TupleTableSlot *oracleExecForeignInsert(EState *estate, ResultRelInfo *rinfo, TupleTableSlot *slot, TupleTableSlot *planSlot);
static TupleTableSlot *oracleExecForeignUpdate(EState *estate, ResultRelInfo *rinfo, TupleTableSlot *slot, TupleTableSlot *planSlot);
static TupleTableSlot *oracleExecForeignDelete(EState *estate, ResultRelInfo *rinfo, TupleTableSlot *slot, TupleTableSlot *planSlot);
static void oracleEndForeignModify(EState *estate, ResultRelInfo *rinfo);
static void oracleExplainForeignModify(ModifyTableState *mtstate, ResultRelInfo *rinfo, List *fdw_private, int subplan_index, struct ExplainState *es);
static int oracleIsForeignRelUpdatable(Relation rel);
#ifdef IMPORT_API
static List *oracleImportForeignSchema(ImportForeignSchemaStmt *stmt, Oid serverOid);
#endif /* IMPORT_API */
/*
* Helper functions
*/
static struct OracleFdwState *getFdwState(Oid foreigntableid, double *sample_percent, Oid userid);
static void oracleGetOptions(Oid foreigntableid, Oid userid, List **options);
static char *createQuery(struct OracleFdwState *fdwState, RelOptInfo *foreignrel, bool for_update, List *query_pathkeys);
static void deparseFromExprForRel(struct OracleFdwState *fdwState, StringInfo buf, RelOptInfo *joinrel, List **params_list);
#ifdef JOIN_API
static void appendConditions(List *exprs, StringInfo buf, RelOptInfo *joinrel, List **params_list);
static bool foreign_join_ok(PlannerInfo *root, RelOptInfo *joinrel, JoinType jointype, RelOptInfo *outerrel, RelOptInfo *innerrel, JoinPathExtraData *extra);
static const char *get_jointype_name(JoinType jointype);
static List *build_tlist_to_deparse(RelOptInfo *foreignrel);
static struct oraTable *build_join_oratable(struct OracleFdwState *fdwState, List *fdw_scan_tlist);
#endif /* JOIN_API */
static void getColumnData(Oid foreigntableid, struct oraTable *oraTable);
static int acquireSampleRowsFunc (Relation relation, int elevel, HeapTuple *rows, int targrows, double *totalrows, double *totaldeadrows);
static void appendAsType(StringInfoData *dest, const char *s, Oid type);
static char *deparseExpr(oracleSession *session, RelOptInfo *foreignrel, Expr *expr, const struct oraTable *oraTable, List **params, bool check_only);
static char *datumToString(Datum datum, Oid type);
static void getUsedColumns(Expr *expr, struct oraTable *oraTable, int foreignrelid);
static void checkDataType(oraType oratype, int scale, Oid pgtype, const char *tablename, const char *colname);
static char *deparseWhereConditions(struct OracleFdwState *fdwState, RelOptInfo *baserel, List **local_conds, List **remote_conds);
static char *guessNlsLang(char *nls_lang);
static char *getTimezone(void);
static oracleSession *oracleConnectServer(Name srvname);
static List *serializePlanData(struct OracleFdwState *fdwState);
static Const *serializeString(const char *s);
static struct OracleFdwState *deserializePlanData(List *list);
static char *deserializeString(Const *constant);
static bool getBoolVal(DefElem *def);
static char *deparseDate(Datum datum);
static char *deparseTimestamp(Datum datum, bool hasTimezone);
static char *deparseInterval(Datum datum);
static char *convertUUID(char *uuid);
static struct OracleFdwState *copyPlanData(struct OracleFdwState *orig);
static void subtransactionCallback(SubXactEvent event, SubTransactionId mySubid, SubTransactionId parentSubid, void *arg);
static void addParam(struct paramDesc **paramList, char *name, Oid pgtype, oraType oratype, int colnum);
static void setModifyParameters(struct paramDesc *paramList, TupleTableSlot *newslot, TupleTableSlot *oldslot, struct oraTable *oraTable, oracleSession *session);
static void transactionCallback(XactEvent event, void *arg);
static void exitHook(int code, Datum arg);
static void oracleDie(SIGNAL_ARGS);
static char *setSelectParameters(struct paramDesc *paramList, ExprContext *econtext);
static void convertTuple(struct OracleFdwState *fdw_state, unsigned int index, Datum *values, bool *nulls, bool trunc_lob);
static void errorContextCallback(void *arg);
static bool hasTrigger(Relation rel, CmdType cmdtype);
static void buildInsertQuery(StringInfo sql, struct OracleFdwState *fdwState);
static void buildUpdateQuery(StringInfo sql, struct OracleFdwState *fdwState, List *targetAttrs);
static void appendReturningClause(StringInfo sql, struct OracleFdwState *fdwState);
#ifdef IMPORT_API
static char *fold_case(char *name, fold_t foldcase, int collation);
#endif /* IMPORT_API */
static oraIsoLevel getIsolationLevel(const char *isolation_level);
static bool pushdownOrderBy(PlannerInfo *root, RelOptInfo *baserel, struct OracleFdwState *fdwState);
#if PG_VERSION_NUM < 150000
/* this is new in PostgreSQL v15 */
struct pg_itm
{
int tm_usec;
int tm_sec;
int tm_min;
int64 tm_hour; /* needs to be wide */
int tm_mday;
int tm_mon;
int tm_year;
};
static void interval2itm(Interval span, struct pg_itm *itm);
#endif /* PG_VERSION_NUM */
#define REL_ALIAS_PREFIX "r"
/* Handy macro to add relation name qualification */
#define ADD_REL_QUALIFIER(buf, varno) \
appendStringInfo((buf), "%s%d.", REL_ALIAS_PREFIX, (varno))
/*
* Foreign-data wrapper handler function: return a struct with pointers
* to callback routines.
*/
PGDLLEXPORT Datum
oracle_fdw_handler(PG_FUNCTION_ARGS)
{
FdwRoutine *fdwroutine = makeNode(FdwRoutine);
fdwroutine->GetForeignRelSize = oracleGetForeignRelSize;
fdwroutine->GetForeignPaths = oracleGetForeignPaths;
#ifdef JOIN_API
fdwroutine->GetForeignJoinPaths = oracleGetForeignJoinPaths;
#endif /* JOIN_API */
fdwroutine->GetForeignPlan = oracleGetForeignPlan;
fdwroutine->AnalyzeForeignTable = oracleAnalyzeForeignTable;
fdwroutine->ExplainForeignScan = oracleExplainForeignScan;
fdwroutine->BeginForeignScan = oracleBeginForeignScan;
fdwroutine->IterateForeignScan = oracleIterateForeignScan;
fdwroutine->ReScanForeignScan = oracleReScanForeignScan;
fdwroutine->EndForeignScan = oracleEndForeignScan;
fdwroutine->AddForeignUpdateTargets = oracleAddForeignUpdateTargets;
fdwroutine->PlanForeignModify = oraclePlanForeignModify;
fdwroutine->BeginForeignModify = oracleBeginForeignModify;
#if PG_VERSION_NUM >= 110000
fdwroutine->BeginForeignInsert = oracleBeginForeignInsert;
fdwroutine->EndForeignInsert = oracleEndForeignInsert;
#endif /*PG_VERSION_NUM */
fdwroutine->ExecForeignInsert = oracleExecForeignInsert;
fdwroutine->ExecForeignUpdate = oracleExecForeignUpdate;
fdwroutine->ExecForeignDelete = oracleExecForeignDelete;
fdwroutine->EndForeignModify = oracleEndForeignModify;
fdwroutine->ExplainForeignModify = oracleExplainForeignModify;
fdwroutine->IsForeignRelUpdatable = oracleIsForeignRelUpdatable;
#ifdef IMPORT_API
fdwroutine->ImportForeignSchema = oracleImportForeignSchema;
#endif /* IMPORT_API */
PG_RETURN_POINTER(fdwroutine);
}
/*
* oracle_fdw_validator
* Validate the generic options given to a FOREIGN DATA WRAPPER, SERVER,
* USER MAPPING or FOREIGN TABLE that uses oracle_fdw.
*
* Raise an ERROR if the option or its value are considered invalid
* or a required option is missing.
*/
PGDLLEXPORT Datum
oracle_fdw_validator(PG_FUNCTION_ARGS)
{
List *options_list = untransformRelOptions(PG_GETARG_DATUM(0));
Oid catalog = PG_GETARG_OID(1);
ListCell *cell;
bool option_given[option_count] = { false };
int i;
/*
* Check that only options supported by oracle_fdw, and allowed for the
* current object type, are given.
*/
foreach(cell, options_list)
{
DefElem *def = (DefElem *)lfirst(cell);
bool opt_found = false;
/* search for the option in the list of valid options */
for (i=0; i<option_count; ++i)
{
if (catalog == valid_options[i].optcontext && strcmp(valid_options[i].optname, def->defname) == 0)
{
opt_found = true;
option_given[i] = true;
break;
}
}
/* option not found, generate error message */
if (!opt_found)
{
/* generate list of options */
StringInfoData buf;
initStringInfo(&buf);
for (i=0; i<option_count; ++i)
{
if (catalog == valid_options[i].optcontext)
appendStringInfo(&buf, "%s%s", (buf.len > 0) ? ", " : "", valid_options[i].optname);
}
ereport(ERROR,
(errcode(ERRCODE_FDW_INVALID_OPTION_NAME),
errmsg("invalid option \"%s\"", def->defname),
errhint("Valid options in this context are: %s", buf.data)));
}
/* check valid values for "isolation_level" */
if (strcmp(def->defname, OPT_ISOLATION_LEVEL) == 0)
(void)getIsolationLevel(strVal(def->arg));
/* check valid values for "readonly", "key", "strip_zeros" and "nchar" */
if (strcmp(def->defname, OPT_READONLY) == 0
|| strcmp(def->defname, OPT_KEY) == 0
|| strcmp(def->defname, OPT_STRIP_ZEROS) == 0
|| strcmp(def->defname, OPT_NCHAR) == 0
|| strcmp(def->defname, OPT_SET_TIMEZONE) == 0)
(void)getBoolVal(def);
/* check valid values for "dblink" */
if (strcmp(def->defname, OPT_DBLINK) == 0)
{
char *val = strVal(def->arg);
if (strchr(val, '"') != NULL)
ereport(ERROR,
(errcode(ERRCODE_FDW_INVALID_ATTRIBUTE_VALUE),
errmsg("invalid value for option \"%s\"", def->defname),
errhint("Double quotes are not allowed in the dblink name.")));
}
/* check valid values for "schema" */
if (strcmp(def->defname, OPT_SCHEMA) == 0)
{
char *val = strVal(def->arg);
if (strchr(val, '"') != NULL)
ereport(ERROR,
(errcode(ERRCODE_FDW_INVALID_ATTRIBUTE_VALUE),
errmsg("invalid value for option \"%s\"", def->defname),
errhint("Double quotes are not allowed in the schema name.")));
}
/* check valid values for max_long */
if (strcmp(def->defname, OPT_MAX_LONG) == 0)
{
char *val = strVal(def->arg);
char *endptr;
unsigned long max_long;
errno = 0;
max_long = strtoul(val, &endptr, 0);
if (val[0] == '\0' || *endptr != '\0' || errno != 0 || max_long < 1 || max_long > 1073741823ul)
ereport(ERROR,
(errcode(ERRCODE_FDW_INVALID_ATTRIBUTE_VALUE),
errmsg("invalid value for option \"%s\"", def->defname),
errhint("Valid values in this context are integers between 1 and 1073741823.")));
}
/* check valid values for "sample_percent" */
if (strcmp(def->defname, OPT_SAMPLE) == 0)
{
char *val = strVal(def->arg);
char *endptr;
double sample_percent;
errno = 0;
sample_percent = strtod(val, &endptr);
if (val[0] == '\0' || *endptr != '\0' || errno != 0 || sample_percent < 0.000001 || sample_percent > 100.0)
ereport(ERROR,
(errcode(ERRCODE_FDW_INVALID_ATTRIBUTE_VALUE),
errmsg("invalid value for option \"%s\"", def->defname),
errhint("Valid values in this context are numbers between 0.000001 and 100.")));
}
/* check valid values for "prefetch" */
if (strcmp(def->defname, OPT_PREFETCH) == 0)
{
char *val = strVal(def->arg);
char *endptr;
long prefetch;
errno = 0;
prefetch = strtol(val, &endptr, 0);
if (val[0] == '\0' || *endptr != '\0' || errno != 0 || prefetch < 1 || prefetch > MAXIMUM_PREFETCH)
ereport(ERROR,
(errcode(ERRCODE_FDW_INVALID_ATTRIBUTE_VALUE),
errmsg("invalid value for option \"%s\"", def->defname),
errhint("Valid values in this context are integers between 1 and %d.", MAXIMUM_PREFETCH)));
}
/* check valid values for "lob_prefetch" */
if (strcmp(def->defname, OPT_LOB_PREFETCH) == 0)
{
char *val = strVal(def->arg);
char *endptr;
long lob_prefetch;
errno = 0;
lob_prefetch = strtol(val, &endptr, 0);
if (val[0] == '\0' || *endptr != '\0' || errno != 0 || lob_prefetch < 0 || lob_prefetch > 536870912 )
ereport(ERROR,
(errcode(ERRCODE_FDW_INVALID_ATTRIBUTE_VALUE),
errmsg("invalid value for option \"%s\"", def->defname),
errhint("Valid values in this context are integers between 0 and 536870912.")));
}
}
/* check that all required options have been given */
for (i=0; i<option_count; ++i)
{
if (catalog == valid_options[i].optcontext && valid_options[i].optrequired && !option_given[i])
{
ereport(ERROR,
(errcode(ERRCODE_FDW_OPTION_NAME_NOT_FOUND),
errmsg("missing required option \"%s\"", valid_options[i].optname)));
}
}
PG_RETURN_VOID();
}
/*
* oracle_close_connections
* Close all open Oracle connections.
*/
PGDLLEXPORT Datum
oracle_close_connections(PG_FUNCTION_ARGS)
{
if (dml_in_transaction)
ereport(ERROR,
(errcode(ERRCODE_ACTIVE_SQL_TRANSACTION),
errmsg("connections with an active transaction cannot be closed"),
errhint("The transaction that modified Oracle data must be closed first.")));
elog(DEBUG1, "oracle_fdw: close all Oracle connections");
oracleCloseConnections();
PG_RETURN_VOID();
}
/*
* oracle_diag
* Get the Oracle client version.
* If a non-NULL argument is supplied, it must be a foreign server name.
* In this case, the remote server version is returned as well.
*/
PGDLLEXPORT Datum
oracle_diag(PG_FUNCTION_ARGS)
{
char *pgversion;
int major, minor, update, patch, port_patch;
StringInfoData version;
/*
* Get the PostgreSQL server version.
* We cannot use PG_VERSION because that would give the version against which
* oracle_fdw was compiled, not the version it is running with.
*/
pgversion = GetConfigOptionByName("server_version", NULL);
/* get the Oracle client version */
oracleClientVersion(&major, &minor, &update, &patch, &port_patch);
initStringInfo(&version);
appendStringInfo(&version, "oracle_fdw %s, PostgreSQL %s, Oracle client %d.%d.%d.%d.%d",
ORACLE_FDW_VERSION,
pgversion,
major, minor, update, patch, port_patch);
if (PG_ARGISNULL(0))
{
/* display some important Oracle environment variables */
static const char * const oracle_env[] = {
"ORACLE_HOME",
"ORACLE_SID",
"TNS_ADMIN",
"TWO_TASK",
"LDAP_ADMIN",
NULL
};
int i;
for (i=0; oracle_env[i] != NULL; ++i)
{
char *val = getenv(oracle_env[i]);
if (val != NULL)
appendStringInfo(&version, ", %s=%s", oracle_env[i], val);
}
}
else
{
oracleSession *session;
Name srvname = PG_GETARG_NAME(0);
session = oracleConnectServer(srvname);
/* get the server version */
oracleServerVersion(session, &major, &minor, &update, &patch, &port_patch);
appendStringInfo(&version, ", Oracle server %d.%d.%d.%d.%d",
major, minor, update, patch, port_patch);
/* free the session (connection will be cached) */
pfree(session);
}
PG_RETURN_TEXT_P(cstring_to_text(version.data));
}
/*
* oracle_execute
* Execute a statement that returns no result values on a foreign server.
*/
PGDLLEXPORT Datum
oracle_execute(PG_FUNCTION_ARGS)
{
Name srvname = PG_GETARG_NAME(0);
char *stmt = text_to_cstring(PG_GETARG_TEXT_PP(1));
oracleSession *session = oracleConnectServer(srvname);
oracleExecuteCall(session, stmt);
/* free the session (connection will be cached) */
pfree(session);
PG_RETURN_VOID();
}
/*
* _PG_init
* Library load-time initalization.
* Sets exitHook() callback for backend shutdown.
*/
void
_PG_init(void)
{
/* check for incompatible server versions */
char *pgver_str = GetConfigOptionByName("server_version_num", NULL);
long pgver = strtol(pgver_str, NULL, 10);
pfree(pgver_str);
if ((pgver >= 90600 && pgver <= 90608)
|| (pgver >= 100000 && pgver <= 100003)
|| (pgver >= 110000 && pgver <= 110010)
|| (pgver >= 120000 && pgver <= 120005)
|| (pgver >= 130000 && pgver <= 130009)
|| (pgver >= 140000 && pgver <= 140006)
|| (pgver >= 150000 && pgver <= 150001))
ereport(ERROR,
(errcode(ERRCODE_EXTERNAL_ROUTINE_INVOCATION_EXCEPTION),
errmsg("PostgreSQL version \"%s\" not supported by oracle_fdw",
GetConfigOptionByName("server_version", NULL)),
errhint("You'll have to update PostgreSQL to a later minor release.")));
/* register an exit hook */
on_proc_exit(&exitHook, PointerGetDatum(NULL));
}
/*
* oracleGetForeignRelSize
* Get an OracleFdwState for this foreign scan.
* Construct the remote SQL query.
* Provide estimates for the number of tuples, the average width and the cost.
*/
void
oracleGetForeignRelSize(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid)
{
struct OracleFdwState *fdwState;
int i;
double ntuples = -1;
RangeTblEntry *rte = planner_rt_fetch(baserel->relid, root);
Oid check_user;
/*
* Get the user whose user mapping should be used (if invalid, the current
* user is used).
*/
#if PG_VERSION_NUM < 160000
check_user = rte->checkAsUser;
#else
check_user = getRTEPermissionInfo(root->parse->rteperminfos, rte)->checkAsUser;
#endif /* PG_VERSION_NUM < 160000 */
elog(DEBUG1, "oracle_fdw: plan foreign table scan");
/*
* Get connection options, connect and get the remote table description.
* To match what ExecCheckRTEPerms does, pass the user whose user mapping
* should be used (if invalid, the current user is used).
*/
fdwState = getFdwState(foreigntableid, NULL, check_user);
/*
* Store the table OID in each table column.
* This is redundant for base relations, but join relations will
* have columns from different tables, and we have to keep track of them.
*/
for (i=0; i<fdwState->oraTable->ncols; ++i){
fdwState->oraTable->cols[i]->varno = baserel->relid;
}
/*
* Classify conditions into remote_conds or local_conds.
* These parameters are used in foreign_join_ok and oracleGetForeignPlan.
* Those conditions that can be pushed down will be collected into
* an Oracle WHERE clause.
*/
fdwState->where_clause = deparseWhereConditions(
fdwState,
baserel,
&(fdwState->local_conds),
&(fdwState->remote_conds)
);
/*
* Determine whether we can potentially push query pathkeys to the remote
* side, avoiding a local sort.
*/
(void) pushdownOrderBy(root, baserel, fdwState);
/* release Oracle session (will be cached) */
pfree(fdwState->session);
fdwState->session = NULL;
/* use a random "high" value for cost */
fdwState->startup_cost = 10000.0;
/* if baserel->pages > 0, there was an ANALYZE; use the row count estimate */
#if PG_VERSION_NUM < 140000
/* before v14, baserel->tuples == 0 for tables that have never been vacuumed */
if (baserel->pages > 0)
#endif /* PG_VERSION_NUM */
ntuples = baserel->tuples;
/* estimale selectivity locally for all conditions */
/* apply statistics only if we have a reasonable row count estimate */
if (ntuples != -1)
{
/* estimate how conditions will influence the row count */
ntuples = ntuples * clauselist_selectivity(root, baserel->baserestrictinfo, 0, JOIN_INNER, NULL);
/* make sure that the estimate is not less that 1 */
ntuples = clamp_row_est(ntuples);
baserel->rows = ntuples;
}
/* estimate total cost as startup cost + 10 * (returned rows) */
fdwState->total_cost = fdwState->startup_cost + baserel->rows * 10.0;
/* store the state so that the other planning functions can use it */
baserel->fdw_private = (void *)fdwState;
}
/* oracleGetForeignPaths
* Create a ForeignPath node and add it as only possible path.
*/
void
oracleGetForeignPaths(PlannerInfo *root, RelOptInfo *baserel, Oid foreigntableid)
{
struct OracleFdwState *fdwState = (struct OracleFdwState *)baserel->fdw_private;
/* add the only path */
add_path(baserel,
(Path *)create_foreignscan_path(
root,
baserel,
#if PG_VERSION_NUM >= 90600
NULL, /* default pathtarget */
#endif /* PG_VERSION_NUM */
baserel->rows,
#if PG_VERSION_NUM >= 180000
0, /* no disabled plan nodes */
#endif /* PG_VERSION_NUM */
fdwState->startup_cost,
fdwState->total_cost,
fdwState->usable_pathkeys,
baserel->lateral_relids,
#if PG_VERSION_NUM >= 90500
NULL, /* no extra plan */
#endif /* PG_VERSION_NUM */
#if PG_VERSION_NUM >= 170000
NIL, /* no fdw_restrictinfo */
#endif /* PG_VERSION_NUM */
NIL
)
);
}
#ifdef JOIN_API
/*
* oracleGetForeignJoinPaths
* Add possible ForeignPath to joinrel if the join is safe to push down.
* For now, we can only push down 2-way joins for SELECT.
*/
static void
oracleGetForeignJoinPaths(PlannerInfo *root,
RelOptInfo *joinrel,
RelOptInfo *outerrel,
RelOptInfo *innerrel,
JoinType jointype,
JoinPathExtraData *extra)
{
struct OracleFdwState *fdwState;
ForeignPath *joinpath;
double joinclauses_selectivity;
double rows; /* estimated number of returned rows */
Cost startup_cost;
Cost total_cost;
/*
* Currently we don't push-down joins in query for UPDATE/DELETE.
* This would require a path for EvalPlanQual.
* This restriction might be relaxed in a later release.
*/
if (root->parse->commandType != CMD_SELECT)
{
elog(DEBUG2, "oracle_fdw: don't push down join because it is no SELECT");
return;
}
if (root->rowMarks)
{
elog(DEBUG2, "oracle_fdw: don't push down join with FOR UPDATE");
return;
}
/*
* N-way join is not supported, due to the column definition infrastracture.
* If we can track relid mapping of join relations, we can support N-way join.
*/
if (! IS_SIMPLE_REL(outerrel) || ! IS_SIMPLE_REL(innerrel))
return;
/* skip if this join combination has been considered already */
if (joinrel->fdw_private)
return;
/*
* Create unfinished OracleFdwState which is used to indicate
* that the join relation has already been considered, so that we won't waste
* time considering it again and don't add the same path a second time.
* Once we know that this join can be pushed down, we fill the data structure.
*/
fdwState = (struct OracleFdwState *) palloc0(sizeof(struct OracleFdwState));
joinrel->fdw_private = fdwState;
/* this performs further checks */
if (!foreign_join_ok(root, joinrel, jointype, outerrel, innerrel, extra))
return;
/* estimate the number of result rows for the join */
#if PG_VERSION_NUM < 140000
if (outerrel->pages > 0 && innerrel->pages > 0)
#else
if (outerrel->tuples >= 0 && innerrel->tuples >= 0)
#endif /* PG_VERSION_NUM */
{
/* both relations have been ANALYZEd, so there should be useful statistics */
joinclauses_selectivity = clauselist_selectivity(root, fdwState->joinclauses, 0, JOIN_INNER, extra->sjinfo);
rows = clamp_row_est(innerrel->tuples * outerrel->tuples * joinclauses_selectivity);
}
else
{
/* at least one table lacks statistics, so use a fixed estimate */
rows = 1000.0;
}
/* use a random "high" value for startup cost */
startup_cost = 10000.0;
/* estimate total cost as startup cost + (returned rows) * 10.0 */
total_cost = startup_cost + rows * 10.0;
/* store cost estimation results */
joinrel->rows = rows;
fdwState->startup_cost = startup_cost;