Improve the performance of the ANALYZE command by taking advantage of

UNIQUE constraints on indices.

FossilOrigin-Name: 114dcf33670fd98a1ebbac0e44f66b2d8bcccddf

diff --cc manifest
index 87c15adf11b1eadff21645498a715fb1e6d398d5,6c8e62a3ab8b5923d1bfca950cc871a3f3bdb39e..a378b1468da55120561a462020fd7d76e7214b95
--- 1/manifest
--- 2/manifest
+++ b/manifest
@@@ -1,5 -1,5 +1,5 @@@
- C Fix\sa\sbug\sin\sthe\swhereRangeSkipScanEst()\sprocedure\s(added\sby\ncheck-in\s[d09ca6d5efad3e4cfa])\swhere\sit\sfails\sto\sconsider\sthe\spossibility\nof\sa\sROWID\scolumn\swhen\scomputing\sthe\saffinity\sof\sa\stable\scolumn.
- D 2014-07-24T22:41:20.186
 -C Avoid\strying\sto\sallocation\szero\sbytes\swhen\sanalyzing\sa\sunique\snon-null\sindex.
 -D 2014-07-24T20:25:16.037
++C Improve\sthe\sperformance\sof\sthe\sANALYZE\scommand\sby\staking\sadvantage\sof\nUNIQUE\sconstraints\son\sindices.
++D 2014-07-24T23:23:26.687
  F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
  F Makefile.in 5eb79e334a5de69c87740edd56af6527dd219308
  F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@@ -161,7 -161,7 +161,7 @@@ F sqlite.pc.in 42b7bf0d02e08b9e77734a47
  F sqlite3.1 3d8b83c91651f53472ca17599dae3457b8b89494
  F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
  F src/alter.c b00900877f766f116f9e16116f1ccacdc21d82f1
- F src/analyze.c 1c9831015e8c575796a97692d1493ba720d16f27
 -F src/analyze.c 9799a65d8e8892e6eb96d0094a1d4fa6d7aebd0e
++F src/analyze.c de34a73b86db9dc3a16beef12cc5573c50223956
  F src/attach.c 3801129015ef59d76bf23c95ef9b0069d18a0c52
  F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
  F src/backup.c a729e63cf5cd1829507cb7b8e89f99b95141bb53
@@@ -1184,7 -1183,7 +1184,8 @@@ F tool/vdbe_profile.tcl 67746953071a9f8
  F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
  F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
  F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
- P fb1048cb2b613a0dbfe625a5df05e9dcd736a433
- R 7154486a7ce11d45d2aed19cdac8eb64
 -P 4690e99c07024f40fafba1db8e4487b287b788a9
 -R 665515c1fc4ab29e7e80bbd8e675bbe2
++P 6aea2258dd7d3967900cefe4cd0af48a7ee7e169 85e2badeeb7f7599eb6fd35512f9bd524f0b1b3f
++R ac28d1873bd62cdf71787453262a0966
++T +closed 85e2badeeb7f7599eb6fd35512f9bd524f0b1b3f
  U drh
- Z 3de5689fcbb67ba500bf3c297659c386
 -Z 06b30e9b7410b92f6a1122ec1ae06529
++Z 72b5de0db489041a156923cd906bfefb

diff --cc manifest.uuid
index 8f811c9bc6c8c853abd82fd719d610ab78d3e963,e165c09bcc3b30ecb7a90771fba8c39ab66127ec..a9e63c9b420cbe2f3b408a8c255e83ba1aeb5e15
--- 1/manifest.uuid
--- 2/manifest.uuid
+++ b/manifest.uuid
@@@ -1,1 -1,1 +1,1 @@@
- 6aea2258dd7d3967900cefe4cd0af48a7ee7e169
 -85e2badeeb7f7599eb6fd35512f9bd524f0b1b3f
++114dcf33670fd98a1ebbac0e44f66b2d8bcccddf

diff --cc src/analyze.c
Simple merge