Fix a comment in vdbesort.c.

FossilOrigin-Name: db8518cab8e329b1dbe4cd6c81b21ef3ea69fcb1
This commit is contained in:
dan
2011-08-04 18:43:37 +00:00
parent c6e734554f
commit f25eef9882
3 changed files with 22 additions and 23 deletions
+6 -6
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@@ -1,5 +1,5 @@
C Change\sto\susing\spacked-memory-arrays\sinstead\sof\sb-trees\swhen\sperforming\san\soffline\smerge-sort\sfor\sCREATE\sINDEX.\sThis\smakes\sit\seasier\sto\scontrol\sthe\snumber\sof\sdisc\sseeks\srequired\swhen\smerging.
D 2011-08-04T12:14:04.747
C Fix\sa\scomment\sin\svdbesort.c.
D 2011-08-04T18:43:37.790
F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
F Makefile.in c1d7a7f4fd8da6b1815032efca950e3d5125407e
F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -245,7 +245,7 @@ F src/vdbeapi.c 11dc47987abacb76ad016dcf5abc0dc422482a98
F src/vdbeaux.c 8fb978eb73a97b34d352dd3ef3bff35b1b3fa7e9
F src/vdbeblob.c f024f0bf420f36b070143c32b15cc7287341ffd3
F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
F src/vdbesort.c e7d1a86ebe0501161988001514c6ce0d0bb76a5a
F src/vdbesort.c 87c3b2921cbfd29a7fd0ef834f29b5a4fd8be56e
F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
F src/vtab.c 901791a47318c0562cd0c676a2c6ff1bc530e582
F src/wal.c 0c70ad7b1cac6005fa5e2cbefd23ee05e391c290
@@ -954,7 +954,7 @@ F tool/symbols.sh caaf6ccc7300fd43353318b44524853e222557d5
F tool/tostr.awk 11760e1b94a5d3dcd42378f3cc18544c06cfa576
F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
F tool/warnings.sh 2ebae31e1eb352696f3c2f7706a34c084b28c262
P 7f339c0e2655310d7530041c379b082d49ce8c7f
R d1224a68c01eeac1a445468ca51c2250
P a4770d079c1b236eb54751e75a44cccc997c6b93
R ec95e9bd54ef30cddfc95ab39fec1eee
U dan
Z 3f3c28dfd1bf55734d647cab0b6dad47
Z 35780c1186756c8599cb8966b7d9180f
+1 -1
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@@ -1 +1 @@
a4770d079c1b236eb54751e75a44cccc997c6b93
db8518cab8e329b1dbe4cd6c81b21ef3ea69fcb1
+15 -16
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@@ -21,24 +21,23 @@
typedef struct VdbeSorterIter VdbeSorterIter;
/*
** The aIter[] and aTree[] arrays are used to iterate through the sorter
** contents after it has been populated. To iterate through the sorter
** contents, the contents of all packed-memory-arrays (PMAs) must be
** merged. This structure supports merging any number of arrays in a
** single pass with no redundant comparison operations.
** As keys are added to the sorter, they are written to disk in a series
** of sorted packed-memory-arrays (PMAs). The size of each PMA is roughly
** the same as the cache-size allowed for temporary databases. In order
** to allow the caller to extract keys from the sorter in sorted order,
** all PMAs currently stored on disk must be merged together. This comment
** describes the data structure used to do so. The structure supports
** merging any number of arrays in a single pass with no redundant comparison
** operations.
**
** TODO: It may turn out that the optimum number of PMAs to merge in a
** single pass is 2. If this is the case, this data structure could be
** simplified.
** The aIter[] array contains an iterator for each of the PMAs being merged.
** An aIter[] iterator either points to a valid key or else is at EOF. For
** the purposes of the paragraphs below, we assume that the array is actually
** N elements in size, where N is the smallest power of 2 greater to or equal
** to the number of iterators being merged. The extra aIter[] elements are
** treated as if they are empty (always at EOF).
**
** The first few elements of the aIter[] array contain pointers into
** each of the PMAs being merged. An aIter[] element either points to a
** valid key or else is at EOF. For the purposes of the paragraphs below,
** we assume that the array is actually N elements in size, where N is the
** smallest power of 2 greater to or equal to nRoot. The extra aIter[]
** elements are treated as if they are empty PMAs (always at EOF).
**
** The aTree[] array is N elements in size. The value of N is stored in
** The aTree[] array is also N elements in size. The value of N is stored in
** the VdbeSorter.nTree variable.
**
** The final (N/2) elements of aTree[] contain the results of comparing