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Reduce default file size limit to 1Gb, and move the

configuration constant to config.h.

1 parent9cae93d commit5ce851dCopy full SHA for 5ce851d

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2 files changed

+23

-29

lines changed

src
- backend/storage/smgr
  - md.c
- include
  - config.h.in

2 files changed

+23

-29

lines changed

`‎src/backend/storage/smgr/md.c`

Lines changed: 6 additions & 29 deletions

Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@`
`7`	`7`	`*`
`8`	`8`	`*`
`9`	`9`	`* IDENTIFICATION`
`10`		`- * $Header: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v 1.41 1999/02/13 23:18:35 momjian Exp $`
	`10`	`+ * $Header: /cvsroot/pgsql/src/backend/storage/smgr/md.c,v 1.42 1999/04/05 22:25:11 tgl Exp $`
`11`	`11`	`*`
`12`	`12`	`*-------------------------------------------------------------------------`
`13`	`13`	`*/`
`@@ -33,10 +33,11 @@`
`33`	`33`	`*The magnetic disk storage manager keeps track of open file descriptors`
`34`	`34`	`*in its own descriptor pool. This happens for two reasons.First, at`
`35`	`35`	`*transaction boundaries, we walk the list of descriptors and flush`
`36`		`- *anything that we've dirtied in the current transaction. Second, we`
`37`		`- *have to support relations of > 4GBytes. In order to do this, we break`
`38`		`- *relations up into chunks of < 2GBytes and store one chunk in each of`
`39`		`- *several files that represent the relation.`
	`36`	`+ *anything that we've dirtied in the current transaction. Second, we want`
	`37`	`+ *to support relations larger than the OS' file size limit (often 2GBytes).`
	`38`	`+ *In order to do that, we break relations up into chunks of < 2GBytes`
	`39`	`+ *and store one chunk in each of several files that represent the relation.`
	`40`	`+ *See the BLCKSZ and RELSEG_SIZE configuration constants in include/config.h.`
`40`	`41`	`*/`
`41`	`42`
`42`	`43`	`typedefstruct_MdfdVec`
`@@ -59,30 +60,6 @@ static MemoryContext MdCxt;`
`59`	`60`	`#defineMDFD_DIRTY(uint16) 0x01`
`60`	`61`	`#defineMDFD_FREE(uint16) 0x02`
`61`	`62`
`62`		`-/*`
`63`		`- * RELSEG_SIZE appears to be the number of segments that can`
`64`		`- * be in a disk file. It was defined as 262144 based on 8k`
`65`		`- * blocks, but now that the block size can be changed, this`
`66`		`- * has to be calculated at compile time. Otherwise, the file`
`67`		`- * size limit would not work out to 2-gig (2147483648).`
`68`		`- *`
`69`		`- * The number needs to be (2 ** 31) / BLCKSZ, but to be keep`
`70`		`- * the math under MAXINT, pre-divide by 256 and use ...`
`71`		`- *`
`72`		`- * (((2 ** 23) / BLCKSZ) * (2 ** 8))`
`73`		`- *`
`74`		`- * 07 Jan 98 darrenk`
`75`		`- *`
`76`		`- * Now possibly let the OS handle it...`
`77`		`- *`
`78`		`- * 19 Mar 98 darrenk`
`79`		`- *`
`80`		`- */`
`81`		`-`
`82`		`-#ifndefLET_OS_MANAGE_FILESIZE`
`83`		`-#defineRELSEG_SIZE((8388608 / BLCKSZ) * 256)`
`84`		`-#endif`
`85`		`-`
`86`	`63`	`/* routines declared here */`
`87`	`64`	`staticMdfdVec*_mdfd_openseg(Relationreln,intsegno,intoflags);`
`88`	`65`	`staticMdfdVec*_mdfd_getseg(Relationreln,intblkno,intoflag);`

`‎src/include/config.h.in`

Lines changed: 17 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -27,6 +27,23 @@`
`27`	`27`	`*/`
`28`	`28`	`#defineBLCKSZ8192`
`29`	`29`
	`30`	`+/*`
	`31`	`+ * RELSEG_SIZE is the maximum number of blocks allowed in one disk file.`
	`32`	`+ * Thus, the maximum size of a single file is RELSEG_SIZE * BLCKSZ;`
	`33`	`+ * relations bigger than that are divided into multiple files.`
	`34`	`+ *`
	`35`	`+ * CAUTION: RELSEG_SIZE * BLCKSZ must be less than your OS' limit on file size.`
	`36`	`+ * This is typically 2Gb or 4Gb in a 32-bit operating system. By default,`
	`37`	`+ * we make the limit one billion bytes to avoid any possible integer-overflow`
	`38`	`+ * problems within the OS. A limit smaller than necessary only means we`
	`39`	`+ * divide a large relation into more chunks than necessary, so it seems best`
	`40`	`+ * to err in the direction of a small limit.`
	`41`	`+ *`
	`42`	`+ * CAUTION: you had best do an initdb if you change either BLCKSZ or`
	`43`	`+ * RELSEG_SIZE.`
	`44`	`+ */`
	`45`	`+#defineRELSEG_SIZE(1000000000 / BLCKSZ)`
	`46`	`+`
`30`	`47`	`/*`
`31`	`48`	`* The following is set using configure.`
`32`	`49`	`*/`

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Commit5ce851d

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2 files changed

2 files changed

`‎src/backend/storage/smgr/md.c`

`‎src/include/config.h.in`

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