1/*
2 * dbsize.c
3 * Database object size functions, and related inquiries
4 *
5 * Copyright (c) 2002-2019, PostgreSQL Global Development Group
6 *
7 * IDENTIFICATION
8 * src/backend/utils/adt/dbsize.c
9 *
10 */
11
12#include "postgres.h"
13
14#include <sys/stat.h>
15
16#include "access/htup_details.h"
17#include "access/relation.h"
18#include "catalog/catalog.h"
19#include "catalog/namespace.h"
20#include "catalog/pg_authid.h"
21#include "catalog/pg_tablespace.h"
22#include "commands/dbcommands.h"
23#include "commands/tablespace.h"
24#include "miscadmin.h"
25#include "storage/fd.h"
26#include "utils/acl.h"
27#include "utils/builtins.h"
28#include "utils/numeric.h"
29#include "utils/rel.h"
30#include "utils/relfilenodemap.h"
31#include "utils/relmapper.h"
32#include "utils/syscache.h"
33
34/* Divide by two and round towards positive infinity. */
35#define half_rounded(x) (((x) + ((x) < 0 ? 0 : 1)) / 2)
36
37/* Return physical size of directory contents, or 0 if dir doesn't exist */
38static int64
39db_dir_size(const char *path)
40{
41 int64 dirsize = 0;
42 struct dirent *direntry;
43 DIR *dirdesc;
44 char filename[MAXPGPATH * 2];
45
46 dirdesc = AllocateDir(path);
47
48 if (!dirdesc)
49 return 0;
50
51 while ((direntry = ReadDir(dirdesc, path)) != NULL)
52 {
53 struct stat fst;
54
55 CHECK_FOR_INTERRUPTS();
56
57 if (strcmp(direntry->d_name, ".") == 0 ||
58 strcmp(direntry->d_name, "..") == 0)
59 continue;
60
61 snprintf(filename, sizeof(filename), "%s/%s", path, direntry->d_name);
62
63 if (stat(filename, &fst) < 0)
64 {
65 if (errno == ENOENT)
66 continue;
67 else
68 ereport(ERROR,
69 (errcode_for_file_access(),
70 errmsg("could not stat file \"%s\": %m", filename)));
71 }
72 dirsize += fst.st_size;
73 }
74
75 FreeDir(dirdesc);
76 return dirsize;
77}
78
79/*
80 * calculate size of database in all tablespaces
81 */
82static int64
83calculate_database_size(Oid dbOid)
84{
85 int64 totalsize;
86 DIR *dirdesc;
87 struct dirent *direntry;
88 char dirpath[MAXPGPATH];
89 char pathname[MAXPGPATH + 21 + sizeof(TABLESPACE_VERSION_DIRECTORY)];
90 AclResult aclresult;
91
92 /*
93 * User must have connect privilege for target database or be a member of
94 * pg_read_all_stats
95 */
96 aclresult = pg_database_aclcheck(dbOid, GetUserId(), ACL_CONNECT);
97 if (aclresult != ACLCHECK_OK &&
98 !is_member_of_role(GetUserId(), DEFAULT_ROLE_READ_ALL_STATS))
99 {
100 aclcheck_error(aclresult, OBJECT_DATABASE,
101 get_database_name(dbOid));
102 }
103
104 /* Shared storage in pg_global is not counted */
105
106 /* Include pg_default storage */
107 snprintf(pathname, sizeof(pathname), "base/%u", dbOid);
108 totalsize = db_dir_size(pathname);
109
110 /* Scan the non-default tablespaces */
111 snprintf(dirpath, MAXPGPATH, "pg_tblspc");
112 dirdesc = AllocateDir(dirpath);
113
114 while ((direntry = ReadDir(dirdesc, dirpath)) != NULL)
115 {
116 CHECK_FOR_INTERRUPTS();
117
118 if (strcmp(direntry->d_name, ".") == 0 ||
119 strcmp(direntry->d_name, "..") == 0)
120 continue;
121
122 snprintf(pathname, sizeof(pathname), "pg_tblspc/%s/%s/%u",
123 direntry->d_name, TABLESPACE_VERSION_DIRECTORY, dbOid);
124 totalsize += db_dir_size(pathname);
125 }
126
127 FreeDir(dirdesc);
128
129 return totalsize;
130}
131
132Datum
133pg_database_size_oid(PG_FUNCTION_ARGS)
134{
135 Oid dbOid = PG_GETARG_OID(0);
136 int64 size;
137
138 size = calculate_database_size(dbOid);
139
140 if (size == 0)
141 PG_RETURN_NULL();
142
143 PG_RETURN_INT64(size);
144}
145
146Datum
147pg_database_size_name(PG_FUNCTION_ARGS)
148{
149 Name dbName = PG_GETARG_NAME(0);
150 Oid dbOid = get_database_oid(NameStr(*dbName), false);
151 int64 size;
152
153 size = calculate_database_size(dbOid);
154
155 if (size == 0)
156 PG_RETURN_NULL();
157
158 PG_RETURN_INT64(size);
159}
160
161
162/*
163 * Calculate total size of tablespace. Returns -1 if the tablespace directory
164 * cannot be found.
165 */
166static int64
167calculate_tablespace_size(Oid tblspcOid)
168{
169 char tblspcPath[MAXPGPATH];
170 char pathname[MAXPGPATH * 2];
171 int64 totalsize = 0;
172 DIR *dirdesc;
173 struct dirent *direntry;
174 AclResult aclresult;
175
176 /*
177 * User must be a member of pg_read_all_stats or have CREATE privilege for
178 * target tablespace, either explicitly granted or implicitly because it
179 * is default for current database.
180 */
181 if (tblspcOid != MyDatabaseTableSpace &&
182 !is_member_of_role(GetUserId(), DEFAULT_ROLE_READ_ALL_STATS))
183 {
184 aclresult = pg_tablespace_aclcheck(tblspcOid, GetUserId(), ACL_CREATE);
185 if (aclresult != ACLCHECK_OK)
186 aclcheck_error(aclresult, OBJECT_TABLESPACE,
187 get_tablespace_name(tblspcOid));
188 }
189
190 if (tblspcOid == DEFAULTTABLESPACE_OID)
191 snprintf(tblspcPath, MAXPGPATH, "base");
192 else if (tblspcOid == GLOBALTABLESPACE_OID)
193 snprintf(tblspcPath, MAXPGPATH, "global");
194 else
195 snprintf(tblspcPath, MAXPGPATH, "pg_tblspc/%u/%s", tblspcOid,
196 TABLESPACE_VERSION_DIRECTORY);
197
198 dirdesc = AllocateDir(tblspcPath);
199
200 if (!dirdesc)
201 return -1;
202
203 while ((direntry = ReadDir(dirdesc, tblspcPath)) != NULL)
204 {
205 struct stat fst;
206
207 CHECK_FOR_INTERRUPTS();
208
209 if (strcmp(direntry->d_name, ".") == 0 ||
210 strcmp(direntry->d_name, "..") == 0)
211 continue;
212
213 snprintf(pathname, sizeof(pathname), "%s/%s", tblspcPath, direntry->d_name);
214
215 if (stat(pathname, &fst) < 0)
216 {
217 if (errno == ENOENT)
218 continue;
219 else
220 ereport(ERROR,
221 (errcode_for_file_access(),
222 errmsg("could not stat file \"%s\": %m", pathname)));
223 }
224
225 if (S_ISDIR(fst.st_mode))
226 totalsize += db_dir_size(pathname);
227
228 totalsize += fst.st_size;
229 }
230
231 FreeDir(dirdesc);
232
233 return totalsize;
234}
235
236Datum
237pg_tablespace_size_oid(PG_FUNCTION_ARGS)
238{
239 Oid tblspcOid = PG_GETARG_OID(0);
240 int64 size;
241
242 size = calculate_tablespace_size(tblspcOid);
243
244 if (size < 0)
245 PG_RETURN_NULL();
246
247 PG_RETURN_INT64(size);
248}
249
250Datum
251pg_tablespace_size_name(PG_FUNCTION_ARGS)
252{
253 Name tblspcName = PG_GETARG_NAME(0);
254 Oid tblspcOid = get_tablespace_oid(NameStr(*tblspcName), false);
255 int64 size;
256
257 size = calculate_tablespace_size(tblspcOid);
258
259 if (size < 0)
260 PG_RETURN_NULL();
261
262 PG_RETURN_INT64(size);
263}
264
265
266/*
267 * calculate size of (one fork of) a relation
268 *
269 * Note: we can safely apply this to temp tables of other sessions, so there
270 * is no check here or at the call sites for that.
271 */
272static int64
273calculate_relation_size(RelFileNode *rfn, BackendId backend, ForkNumber forknum)
274{
275 int64 totalsize = 0;
276 char *relationpath;
277 char pathname[MAXPGPATH];
278 unsigned int segcount = 0;
279
280 relationpath = relpathbackend(*rfn, backend, forknum);
281
282 for (segcount = 0;; segcount++)
283 {
284 struct stat fst;
285
286 CHECK_FOR_INTERRUPTS();
287
288 if (segcount == 0)
289 snprintf(pathname, MAXPGPATH, "%s",
290 relationpath);
291 else
292 snprintf(pathname, MAXPGPATH, "%s.%u",
293 relationpath, segcount);
294
295 if (stat(pathname, &fst) < 0)
296 {
297 if (errno == ENOENT)
298 break;
299 else
300 ereport(ERROR,
301 (errcode_for_file_access(),
302 errmsg("could not stat file \"%s\": %m", pathname)));
303 }
304 totalsize += fst.st_size;
305 }
306
307 return totalsize;
308}
309
310Datum
311pg_relation_size(PG_FUNCTION_ARGS)
312{
313 Oid relOid = PG_GETARG_OID(0);
314 text *forkName = PG_GETARG_TEXT_PP(1);
315 Relation rel;
316 int64 size;
317
318 rel = try_relation_open(relOid, AccessShareLock);
319
320 /*
321 * Before 9.2, we used to throw an error if the relation didn't exist, but
322 * that makes queries like "SELECT pg_relation_size(oid) FROM pg_class"
323 * less robust, because while we scan pg_class with an MVCC snapshot,
324 * someone else might drop the table. It's better to return NULL for
325 * already-dropped tables than throw an error and abort the whole query.
326 */
327 if (rel == NULL)
328 PG_RETURN_NULL();
329
330 size = calculate_relation_size(&(rel->rd_node), rel->rd_backend,
331 forkname_to_number(text_to_cstring(forkName)));
332
333 relation_close(rel, AccessShareLock);
334
335 PG_RETURN_INT64(size);
336}
337
338/*
339 * Calculate total on-disk size of a TOAST relation, including its indexes.
340 * Must not be applied to non-TOAST relations.
341 */
342static int64
343calculate_toast_table_size(Oid toastrelid)
344{
345 int64 size = 0;
346 Relation toastRel;
347 ForkNumber forkNum;
348 ListCell *lc;
349 List *indexlist;
350
351 toastRel = relation_open(toastrelid, AccessShareLock);
352
353 /* toast heap size, including FSM and VM size */
354 for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
355 size += calculate_relation_size(&(toastRel->rd_node),
356 toastRel->rd_backend, forkNum);
357
358 /* toast index size, including FSM and VM size */
359 indexlist = RelationGetIndexList(toastRel);
360
361 /* Size is calculated using all the indexes available */
362 foreach(lc, indexlist)
363 {
364 Relation toastIdxRel;
365
366 toastIdxRel = relation_open(lfirst_oid(lc),
367 AccessShareLock);
368 for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
369 size += calculate_relation_size(&(toastIdxRel->rd_node),
370 toastIdxRel->rd_backend, forkNum);
371
372 relation_close(toastIdxRel, AccessShareLock);
373 }
374 list_free(indexlist);
375 relation_close(toastRel, AccessShareLock);
376
377 return size;
378}
379
380/*
381 * Calculate total on-disk size of a given table,
382 * including FSM and VM, plus TOAST table if any.
383 * Indexes other than the TOAST table's index are not included.
384 *
385 * Note that this also behaves sanely if applied to an index or toast table;
386 * those won't have attached toast tables, but they can have multiple forks.
387 */
388static int64
389calculate_table_size(Relation rel)
390{
391 int64 size = 0;
392 ForkNumber forkNum;
393
394 /*
395 * heap size, including FSM and VM
396 */
397 for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
398 size += calculate_relation_size(&(rel->rd_node), rel->rd_backend,
399 forkNum);
400
401 /*
402 * Size of toast relation
403 */
404 if (OidIsValid(rel->rd_rel->reltoastrelid))
405 size += calculate_toast_table_size(rel->rd_rel->reltoastrelid);
406
407 return size;
408}
409
410/*
411 * Calculate total on-disk size of all indexes attached to the given table.
412 *
413 * Can be applied safely to an index, but you'll just get zero.
414 */
415static int64
416calculate_indexes_size(Relation rel)
417{
418 int64 size = 0;
419
420 /*
421 * Aggregate all indexes on the given relation
422 */
423 if (rel->rd_rel->relhasindex)
424 {
425 List *index_oids = RelationGetIndexList(rel);
426 ListCell *cell;
427
428 foreach(cell, index_oids)
429 {
430 Oid idxOid = lfirst_oid(cell);
431 Relation idxRel;
432 ForkNumber forkNum;
433
434 idxRel = relation_open(idxOid, AccessShareLock);
435
436 for (forkNum = 0; forkNum <= MAX_FORKNUM; forkNum++)
437 size += calculate_relation_size(&(idxRel->rd_node),
438 idxRel->rd_backend,
439 forkNum);
440
441 relation_close(idxRel, AccessShareLock);
442 }
443
444 list_free(index_oids);
445 }
446
447 return size;
448}
449
450Datum
451pg_table_size(PG_FUNCTION_ARGS)
452{
453 Oid relOid = PG_GETARG_OID(0);
454 Relation rel;
455 int64 size;
456
457 rel = try_relation_open(relOid, AccessShareLock);
458
459 if (rel == NULL)
460 PG_RETURN_NULL();
461
462 size = calculate_table_size(rel);
463
464 relation_close(rel, AccessShareLock);
465
466 PG_RETURN_INT64(size);
467}
468
469Datum
470pg_indexes_size(PG_FUNCTION_ARGS)
471{
472 Oid relOid = PG_GETARG_OID(0);
473 Relation rel;
474 int64 size;
475
476 rel = try_relation_open(relOid, AccessShareLock);
477
478 if (rel == NULL)
479 PG_RETURN_NULL();
480
481 size = calculate_indexes_size(rel);
482
483 relation_close(rel, AccessShareLock);
484
485 PG_RETURN_INT64(size);
486}
487
488/*
489 * Compute the on-disk size of all files for the relation,
490 * including heap data, index data, toast data, FSM, VM.
491 */
492static int64
493calculate_total_relation_size(Relation rel)
494{
495 int64 size;
496
497 /*
498 * Aggregate the table size, this includes size of the heap, toast and
499 * toast index with free space and visibility map
500 */
501 size = calculate_table_size(rel);
502
503 /*
504 * Add size of all attached indexes as well
505 */
506 size += calculate_indexes_size(rel);
507
508 return size;
509}
510
511Datum
512pg_total_relation_size(PG_FUNCTION_ARGS)
513{
514 Oid relOid = PG_GETARG_OID(0);
515 Relation rel;
516 int64 size;
517
518 rel = try_relation_open(relOid, AccessShareLock);
519
520 if (rel == NULL)
521 PG_RETURN_NULL();
522
523 size = calculate_total_relation_size(rel);
524
525 relation_close(rel, AccessShareLock);
526
527 PG_RETURN_INT64(size);
528}
529
530/*
531 * formatting with size units
532 */
533Datum
534pg_size_pretty(PG_FUNCTION_ARGS)
535{
536 int64 size = PG_GETARG_INT64(0);
537 char buf[64];
538 int64 limit = 10 * 1024;
539 int64 limit2 = limit * 2 - 1;
540
541 if (Abs(size) < limit)
542 snprintf(buf, sizeof(buf), INT64_FORMAT " bytes", size);
543 else
544 {
545 size >>= 9; /* keep one extra bit for rounding */
546 if (Abs(size) < limit2)
547 snprintf(buf, sizeof(buf), INT64_FORMAT " kB",
548 half_rounded(size));
549 else
550 {
551 size >>= 10;
552 if (Abs(size) < limit2)
553 snprintf(buf, sizeof(buf), INT64_FORMAT " MB",
554 half_rounded(size));
555 else
556 {
557 size >>= 10;
558 if (Abs(size) < limit2)
559 snprintf(buf, sizeof(buf), INT64_FORMAT " GB",
560 half_rounded(size));
561 else
562 {
563 size >>= 10;
564 snprintf(buf, sizeof(buf), INT64_FORMAT " TB",
565 half_rounded(size));
566 }
567 }
568 }
569 }
570
571 PG_RETURN_TEXT_P(cstring_to_text(buf));
572}
573
574static char *
575numeric_to_cstring(Numeric n)
576{
577 Datum d = NumericGetDatum(n);
578
579 return DatumGetCString(DirectFunctionCall1(numeric_out, d));
580}
581
582static Numeric
583int64_to_numeric(int64 v)
584{
585 Datum d = Int64GetDatum(v);
586
587 return DatumGetNumeric(DirectFunctionCall1(int8_numeric, d));
588}
589
590static bool
591numeric_is_less(Numeric a, Numeric b)
592{
593 Datum da = NumericGetDatum(a);
594 Datum db = NumericGetDatum(b);
595
596 return DatumGetBool(DirectFunctionCall2(numeric_lt, da, db));
597}
598
599static Numeric
600numeric_absolute(Numeric n)
601{
602 Datum d = NumericGetDatum(n);
603 Datum result;
604
605 result = DirectFunctionCall1(numeric_abs, d);
606 return DatumGetNumeric(result);
607}
608
609static Numeric
610numeric_half_rounded(Numeric n)
611{
612 Datum d = NumericGetDatum(n);
613 Datum zero;
614 Datum one;
615 Datum two;
616 Datum result;
617
618 zero = DirectFunctionCall1(int8_numeric, Int64GetDatum(0));
619 one = DirectFunctionCall1(int8_numeric, Int64GetDatum(1));
620 two = DirectFunctionCall1(int8_numeric, Int64GetDatum(2));
621
622 if (DatumGetBool(DirectFunctionCall2(numeric_ge, d, zero)))
623 d = DirectFunctionCall2(numeric_add, d, one);
624 else
625 d = DirectFunctionCall2(numeric_sub, d, one);
626
627 result = DirectFunctionCall2(numeric_div_trunc, d, two);
628 return DatumGetNumeric(result);
629}
630
631static Numeric
632numeric_shift_right(Numeric n, unsigned count)
633{
634 Datum d = NumericGetDatum(n);
635 Datum divisor_int64;
636 Datum divisor_numeric;
637 Datum result;
638
639 divisor_int64 = Int64GetDatum((int64) (1 << count));
640 divisor_numeric = DirectFunctionCall1(int8_numeric, divisor_int64);
641 result = DirectFunctionCall2(numeric_div_trunc, d, divisor_numeric);
642 return DatumGetNumeric(result);
643}
644
645Datum
646pg_size_pretty_numeric(PG_FUNCTION_ARGS)
647{
648 Numeric size = PG_GETARG_NUMERIC(0);
649 Numeric limit,
650 limit2;
651 char *result;
652
653 limit = int64_to_numeric(10 * 1024);
654 limit2 = int64_to_numeric(10 * 1024 * 2 - 1);
655
656 if (numeric_is_less(numeric_absolute(size), limit))
657 {
658 result = psprintf("%s bytes", numeric_to_cstring(size));
659 }
660 else
661 {
662 /* keep one extra bit for rounding */
663 /* size >>= 9 */
664 size = numeric_shift_right(size, 9);
665
666 if (numeric_is_less(numeric_absolute(size), limit2))
667 {
668 size = numeric_half_rounded(size);
669 result = psprintf("%s kB", numeric_to_cstring(size));
670 }
671 else
672 {
673 /* size >>= 10 */
674 size = numeric_shift_right(size, 10);
675 if (numeric_is_less(numeric_absolute(size), limit2))
676 {
677 size = numeric_half_rounded(size);
678 result = psprintf("%s MB", numeric_to_cstring(size));
679 }
680 else
681 {
682 /* size >>= 10 */
683 size = numeric_shift_right(size, 10);
684
685 if (numeric_is_less(numeric_absolute(size), limit2))
686 {
687 size = numeric_half_rounded(size);
688 result = psprintf("%s GB", numeric_to_cstring(size));
689 }
690 else
691 {
692 /* size >>= 10 */
693 size = numeric_shift_right(size, 10);
694 size = numeric_half_rounded(size);
695 result = psprintf("%s TB", numeric_to_cstring(size));
696 }
697 }
698 }
699 }
700
701 PG_RETURN_TEXT_P(cstring_to_text(result));
702}
703
704/*
705 * Convert a human-readable size to a size in bytes
706 */
707Datum
708pg_size_bytes(PG_FUNCTION_ARGS)
709{
710 text *arg = PG_GETARG_TEXT_PP(0);
711 char *str,
712 *strptr,
713 *endptr;
714 char saved_char;
715 Numeric num;
716 int64 result;
717 bool have_digits = false;
718
719 str = text_to_cstring(arg);
720
721 /* Skip leading whitespace */
722 strptr = str;
723 while (isspace((unsigned char) *strptr))
724 strptr++;
725
726 /* Check that we have a valid number and determine where it ends */
727 endptr = strptr;
728
729 /* Part (1): sign */
730 if (*endptr == '-' || *endptr == '+')
731 endptr++;
732
733 /* Part (2): main digit string */
734 if (isdigit((unsigned char) *endptr))
735 {
736 have_digits = true;
737 do
738 endptr++;
739 while (isdigit((unsigned char) *endptr));
740 }
741
742 /* Part (3): optional decimal point and fractional digits */
743 if (*endptr == '.')
744 {
745 endptr++;
746 if (isdigit((unsigned char) *endptr))
747 {
748 have_digits = true;
749 do
750 endptr++;
751 while (isdigit((unsigned char) *endptr));
752 }
753 }
754
755 /* Complain if we don't have a valid number at this point */
756 if (!have_digits)
757 ereport(ERROR,
758 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
759 errmsg("invalid size: \"%s\"", str)));
760
761 /* Part (4): optional exponent */
762 if (*endptr == 'e' || *endptr == 'E')
763 {
764 long exponent;
765 char *cp;
766
767 /*
768 * Note we might one day support EB units, so if what follows 'E'
769 * isn't a number, just treat it all as a unit to be parsed.
770 */
771 exponent = strtol(endptr + 1, &cp, 10);
772 (void) exponent; /* Silence -Wunused-result warnings */
773 if (cp > endptr + 1)
774 endptr = cp;
775 }
776
777 /*
778 * Parse the number, saving the next character, which may be the first
779 * character of the unit string.
780 */
781 saved_char = *endptr;
782 *endptr = '\0';
783
784 num = DatumGetNumeric(DirectFunctionCall3(numeric_in,
785 CStringGetDatum(strptr),
786 ObjectIdGetDatum(InvalidOid),
787 Int32GetDatum(-1)));
788
789 *endptr = saved_char;
790
791 /* Skip whitespace between number and unit */
792 strptr = endptr;
793 while (isspace((unsigned char) *strptr))
794 strptr++;
795
796 /* Handle possible unit */
797 if (*strptr != '\0')
798 {
799 int64 multiplier = 0;
800
801 /* Trim any trailing whitespace */
802 endptr = str + VARSIZE_ANY_EXHDR(arg) - 1;
803
804 while (isspace((unsigned char) *endptr))
805 endptr--;
806
807 endptr++;
808 *endptr = '\0';
809
810 /* Parse the unit case-insensitively */
811 if (pg_strcasecmp(strptr, "bytes") == 0)
812 multiplier = (int64) 1;
813 else if (pg_strcasecmp(strptr, "kb") == 0)
814 multiplier = (int64) 1024;
815 else if (pg_strcasecmp(strptr, "mb") == 0)
816 multiplier = ((int64) 1024) * 1024;
817
818 else if (pg_strcasecmp(strptr, "gb") == 0)
819 multiplier = ((int64) 1024) * 1024 * 1024;
820
821 else if (pg_strcasecmp(strptr, "tb") == 0)
822 multiplier = ((int64) 1024) * 1024 * 1024 * 1024;
823
824 else
825 ereport(ERROR,
826 (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
827 errmsg("invalid size: \"%s\"", text_to_cstring(arg)),
828 errdetail("Invalid size unit: \"%s\".", strptr),
829 errhint("Valid units are \"bytes\", \"kB\", \"MB\", \"GB\", and \"TB\".")));
830
831 if (multiplier > 1)
832 {
833 Numeric mul_num;
834
835 mul_num = DatumGetNumeric(DirectFunctionCall1(int8_numeric,
836 Int64GetDatum(multiplier)));
837
838 num = DatumGetNumeric(DirectFunctionCall2(numeric_mul,
839 NumericGetDatum(mul_num),
840 NumericGetDatum(num)));
841 }
842 }
843
844 result = DatumGetInt64(DirectFunctionCall1(numeric_int8,
845 NumericGetDatum(num)));
846
847 PG_RETURN_INT64(result);
848}
849
850/*
851 * Get the filenode of a relation
852 *
853 * This is expected to be used in queries like
854 * SELECT pg_relation_filenode(oid) FROM pg_class;
855 * That leads to a couple of choices. We work from the pg_class row alone
856 * rather than actually opening each relation, for efficiency. We don't
857 * fail if we can't find the relation --- some rows might be visible in
858 * the query's MVCC snapshot even though the relations have been dropped.
859 * (Note: we could avoid using the catcache, but there's little point
860 * because the relation mapper also works "in the now".) We also don't
861 * fail if the relation doesn't have storage. In all these cases it
862 * seems better to quietly return NULL.
863 */
864Datum
865pg_relation_filenode(PG_FUNCTION_ARGS)
866{
867 Oid relid = PG_GETARG_OID(0);
868 Oid result;
869 HeapTuple tuple;
870 Form_pg_class relform;
871
872 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
873 if (!HeapTupleIsValid(tuple))
874 PG_RETURN_NULL();
875 relform = (Form_pg_class) GETSTRUCT(tuple);
876
877 switch (relform->relkind)
878 {
879 case RELKIND_RELATION:
880 case RELKIND_MATVIEW:
881 case RELKIND_INDEX:
882 case RELKIND_SEQUENCE:
883 case RELKIND_TOASTVALUE:
884 /* okay, these have storage */
885 if (relform->relfilenode)
886 result = relform->relfilenode;
887 else /* Consult the relation mapper */
888 result = RelationMapOidToFilenode(relid,
889 relform->relisshared);
890 break;
891
892 default:
893 /* no storage, return NULL */
894 result = InvalidOid;
895 break;
896 }
897
898 ReleaseSysCache(tuple);
899
900 if (!OidIsValid(result))
901 PG_RETURN_NULL();
902
903 PG_RETURN_OID(result);
904}
905
906/*
907 * Get the relation via (reltablespace, relfilenode)
908 *
909 * This is expected to be used when somebody wants to match an individual file
910 * on the filesystem back to its table. That's not trivially possible via
911 * pg_class, because that doesn't contain the relfilenodes of shared and nailed
912 * tables.
913 *
914 * We don't fail but return NULL if we cannot find a mapping.
915 *
916 * InvalidOid can be passed instead of the current database's default
917 * tablespace.
918 */
919Datum
920pg_filenode_relation(PG_FUNCTION_ARGS)
921{
922 Oid reltablespace = PG_GETARG_OID(0);
923 Oid relfilenode = PG_GETARG_OID(1);
924 Oid heaprel = InvalidOid;
925
926 heaprel = RelidByRelfilenode(reltablespace, relfilenode);
927
928 if (!OidIsValid(heaprel))
929 PG_RETURN_NULL();
930 else
931 PG_RETURN_OID(heaprel);
932}
933
934/*
935 * Get the pathname (relative to $PGDATA) of a relation
936 *
937 * See comments for pg_relation_filenode.
938 */
939Datum
940pg_relation_filepath(PG_FUNCTION_ARGS)
941{
942 Oid relid = PG_GETARG_OID(0);
943 HeapTuple tuple;
944 Form_pg_class relform;
945 RelFileNode rnode;
946 BackendId backend;
947 char *path;
948
949 tuple = SearchSysCache1(RELOID, ObjectIdGetDatum(relid));
950 if (!HeapTupleIsValid(tuple))
951 PG_RETURN_NULL();
952 relform = (Form_pg_class) GETSTRUCT(tuple);
953
954 switch (relform->relkind)
955 {
956 case RELKIND_RELATION:
957 case RELKIND_MATVIEW:
958 case RELKIND_INDEX:
959 case RELKIND_SEQUENCE:
960 case RELKIND_TOASTVALUE:
961 /* okay, these have storage */
962
963 /* This logic should match RelationInitPhysicalAddr */
964 if (relform->reltablespace)
965 rnode.spcNode = relform->reltablespace;
966 else
967 rnode.spcNode = MyDatabaseTableSpace;
968 if (rnode.spcNode == GLOBALTABLESPACE_OID)
969 rnode.dbNode = InvalidOid;
970 else
971 rnode.dbNode = MyDatabaseId;
972 if (relform->relfilenode)
973 rnode.relNode = relform->relfilenode;
974 else /* Consult the relation mapper */
975 rnode.relNode = RelationMapOidToFilenode(relid,
976 relform->relisshared);
977 break;
978
979 default:
980 /* no storage, return NULL */
981 rnode.relNode = InvalidOid;
982 /* some compilers generate warnings without these next two lines */
983 rnode.dbNode = InvalidOid;
984 rnode.spcNode = InvalidOid;
985 break;
986 }
987
988 if (!OidIsValid(rnode.relNode))
989 {
990 ReleaseSysCache(tuple);
991 PG_RETURN_NULL();
992 }
993
994 /* Determine owning backend. */
995 switch (relform->relpersistence)
996 {
997 case RELPERSISTENCE_UNLOGGED:
998 case RELPERSISTENCE_PERMANENT:
999 backend = InvalidBackendId;
1000 break;
1001 case RELPERSISTENCE_TEMP:
1002 if (isTempOrTempToastNamespace(relform->relnamespace))
1003 backend = BackendIdForTempRelations();
1004 else
1005 {
1006 /* Do it the hard way. */
1007 backend = GetTempNamespaceBackendId(relform->relnamespace);
1008 Assert(backend != InvalidBackendId);
1009 }
1010 break;
1011 default:
1012 elog(ERROR, "invalid relpersistence: %c", relform->relpersistence);
1013 backend = InvalidBackendId; /* placate compiler */
1014 break;
1015 }
1016
1017 ReleaseSysCache(tuple);
1018
1019 path = relpathbackend(rnode, backend, MAIN_FORKNUM);
1020
1021 PG_RETURN_TEXT_P(cstring_to_text(path));
1022}
1023