Faster operation for large in-memory databases.

FossilOrigin-Name: 9675518b33e8d40769daefb860dc748113f750b6

diff --cc manifest
index acfaf94242b8300c2ff935d6dec734875d10798f,4a83e54278d28fadf539eeb0a0474306dd164c78..a14a5ca3c0e04a3e1648e8a2c21e8d04ba362a50
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,8 -1,8 +1,8 @@@
- C Performance\soptimization\sin\ssqlite3PagerWrite().
- D 2016-12-12T11:05:15.832
 -C Experimental\schanges\sfor\sfaster\sin-memory\sDB\soperation\sfor\slarge\sdatabases.
 -D 2016-11-17T21:52:08.779
 -F Makefile.in 6b572807415d3f0a379cebc9461416d8df4a12c8
++C Faster\soperation\sfor\slarge\sin-memory\sdatabases.
++D 2016-12-12T16:08:44.373
 +F Makefile.in 7639c6a09da11a9c7c6f2630fc981ee588d1072d
  F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 -F Makefile.msc bb4d970894abbbe0e88d00aac29bd52af8bc95f4
 +F Makefile.msc b8ca53350ae545e3562403d5da2a69cec79308da
  F README.md 8ecc12493ff9f820cdea6520a9016001cb2e59b7
  F VERSION 661b3e6a778cfbfd7bdce8bbb1545b22f4b6f09e
  F aclocal.m4 a5c22d164aff7ed549d53a90fa56d56955281f50
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- F src/pager.c b6f38fc2f0da8eafe6ccfbf0b12e228b2ce5fb76
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 -F src/parse.y 0338f906b61e311c2b7e11a3f89b0092c780b664
 -F src/pcache.c 5ff2a08f76a9c1b22f43eb063b7068fb085465ac
++F src/pager.c eaf8590131ab651420e86e89c3fd12d729f55ad3
 +F src/pager.h d1e944291030351f362a0a7da9b5c3e34e603e39
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  F src/pcache1.c e3967219b2a92b9edcb9324a4ba75009090d3953
  F src/pragma.c d932ba278654617cdd281f88a790a3185fca7c44
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 -T -sym-trunk *
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diff --cc manifest.uuid
index cdd0155282294b3e7d3d76f52887dd56dc847199,831b681562b93cb54c0f2c876a45ec0dc64ddbe8..ce37cd3aa69929b5ec16cd5037ab4c1392ea0aaf
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- d4dff10a3d4edf8e1cc77c0a4f185d33f2c2e953
 -4fe94b0f1841180dfd8cac33838e335dc6a428bf
++9675518b33e8d40769daefb860dc748113f750b6

diff --cc src/pager.c
Simple merge