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query planner stuff

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some gcc -Wall fixes
added suport for _ in identifier names in SQL
gmdb2 manual additions
This commit is contained in:
brianb
2003-01-20 16:04:24 +00:00
parent bafa51bd88
commit 092e2b79af
34 changed files with 1143 additions and 382 deletions
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197
src/libmdb/index.c
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@@ -58,7 +58,7 @@ mdb_read_indices(MdbTableDef *table)
{
MdbHandle *mdb = table->entry->mdb;
MdbIndex idx, *pidx;
int len, i, j;
int i, j;
int idx_num, key_num, col_num;
int cur_pos;
int name_sz;
@@ -127,6 +127,7 @@ int name_sz;
cur_pos += 4;
pidx->flags = mdb->pg_buf[cur_pos++];
}
return NULL;
}
void
mdb_index_hash_text(guchar *text, guchar *hash)
@@ -147,8 +148,8 @@ mdb_index_swap_int32(guint32 l)
unsigned char *c, *c2;
guint32 l2;
c = &l;
c2 = &l2;
c = (unsigned char *) &l;
c2 = (unsigned char *) &l2;
c2[0]=c[3];
c2[1]=c[2];
c2[2]=c[1];
@@ -156,9 +157,10 @@ mdb_index_swap_int32(guint32 l)
return l2;
}
void mdb_index_cache_sarg(MdbColumn *col, MdbSarg *sarg, MdbSarg *idx_sarg)
void
mdb_index_cache_sarg(MdbColumn *col, MdbSarg *sarg, MdbSarg *idx_sarg)
{
guint32 cache_int;
//guint32 cache_int;
unsigned char *c;
switch (col->col_type) {
@@ -169,7 +171,7 @@ void mdb_index_cache_sarg(MdbColumn *col, MdbSarg *sarg, MdbSarg *idx_sarg)
case MDB_LONGINT:
idx_sarg->value.i = mdb_index_swap_int32(sarg->value.i);
//cache_int = sarg->value.i * -1;
c = &(idx_sarg->value.i);
c = (unsigned char *) &(idx_sarg->value.i);
c[0] |= 0x80;
//printf("int %08x %02x %02x %02x %02x\n", sarg->value.i, c[0], c[1], c[2], c[3]);
break;
@@ -181,6 +183,33 @@ void mdb_index_cache_sarg(MdbColumn *col, MdbSarg *sarg, MdbSarg *idx_sarg)
break;
}
}
int
mdb_index_test_sarg(MdbHandle *mdb, MdbColumn *col, MdbSarg *sarg, int offset, int len)
{
char tmpbuf[256];
int lastchar;
switch (col->col_type) {
case MDB_BYTE:
return mdb_test_int(sarg, mdb_get_byte(mdb, offset));
break;
case MDB_INT:
return mdb_test_int(sarg, mdb_get_int16(mdb, offset));
break;
case MDB_LONGINT:
return mdb_test_int(sarg, mdb_get_int32(mdb, offset));
break;
case MDB_TEXT:
strncpy(tmpbuf, &mdb->pg_buf[offset],255);
lastchar = len > 255 ? 255 : len;
tmpbuf[lastchar]='\0';
return mdb_test_string(sarg, tmpbuf);
default:
fprintf(stderr, "Calling mdb_test_sarg on unknown type. Add code to mdb_test_sarg() for type %d\n",col->col_type);
break;
}
return 1;
}
int
mdb_index_test_sargs(MdbHandle *mdb, MdbIndex *idx, int offset, int len)
{
@@ -189,6 +218,7 @@ mdb_index_test_sargs(MdbHandle *mdb, MdbIndex *idx, int offset, int len)
MdbTableDef *table = idx->table;
MdbSarg *idx_sarg;
MdbSarg *sarg;
MdbSargNode node;
int c_offset = 0, c_len;
for (i=0;i<idx->num_keys;i++) {
@@ -220,9 +250,12 @@ mdb_index_test_sargs(MdbHandle *mdb, MdbIndex *idx, int offset, int len)
for (j=0;j<col->num_sargs;j++) {
sarg = g_ptr_array_index (col->idx_sarg_cache, j);
if (!mdb_test_sarg(mdb, col, sarg, offset + c_offset, c_len)) {
/* sarg didn't match, no sense going on */
return 0;
/* XXX - kludge */
node.op = sarg->op;
node.value = sarg->value;
if (!mdb_test_sarg(col, &node, &mdb->pg_buf[offset + c_offset], c_len)) {
/* sarg didn't match, no sense going on */
return 0;
}
}
}
@@ -300,7 +333,7 @@ mdb_find_next_leaf(MdbHandle *mdb, MdbIndexChain *chain)
*/
chain->cur_depth++;
if (chain->cur_depth > MDB_MAX_INDEX_DEPTH) {
fprintf(stderr,"Error! maximum index depth of %d exceeded. This is probably due to a programming bug, If you are confident that your indexes really are this deep, adjust MDB_MAX_INDEX_DEPTH in mdbtools.h and recompile.\n");
fprintf(stderr,"Error! maximum index depth of %d exceeded. This is probably due to a programming bug, If you are confident that your indexes really are this deep, adjust MDB_MAX_INDEX_DEPTH in mdbtools.h and recompile.\n", MDB_MAX_INDEX_DEPTH);
exit(1);
}
newipg = &(chain->pages[chain->cur_depth - 1]);
@@ -403,7 +436,7 @@ int i;
for (i=0;i<idx->num_keys;i++) {
marker = mdb->pg_buf[cur_pos++];
col=g_ptr_array_index(table->columns,idx->key_col_num[i]-1);
printf("column %d coltype %d col_size %d (%d)\n",i,col->col_type, mdb_col_fixed_size(col), col->col_size);
//printf("column %d coltype %d col_size %d (%d)\n",i,col->col_type, mdb_col_fixed_size(col), col->col_size);
}
}
void
@@ -428,3 +461,145 @@ mdb_index_dump(MdbTableDef *table, MdbIndex *idx)
}
mdb_index_walk(table, idx);
}
int mdb_index_compute_cost(MdbTableDef *table, MdbIndex *idx)
{
int i;
MdbColumn *col;
MdbSarg *sarg;
int not_all_equal = 0;
if (!idx->num_keys) return 0;
if (idx->num_keys > 1) {
for (i=0;i<idx->num_keys;i++) {
col=g_ptr_array_index(table->columns,idx->key_col_num[i]-1);
sarg = g_ptr_array_index (col->sargs, 0);
if (!sarg || sarg->op != MDB_EQUAL) not_all_equal++;
}
}
col=g_ptr_array_index(table->columns,idx->key_col_num[0]-1);
/*
* if this is the first key column and there are no sargs,
* then this index is useless.
*/
if (!col->num_sargs) return 0;
sarg = g_ptr_array_index (col->sargs, 0);
/*
* a like with a wild card first is useless as a sarg */
if (sarg->op == MDB_LIKE && sarg->value.s[0]=='%')
return 0;
/*
* this needs a lot of tweaking.
*/
if (idx->flags & MDB_IDX_UNIQUE) {
if (idx->num_keys == 1) {
//printf("op is %d\n", sarg->op);
switch (sarg->op) {
case MDB_EQUAL:
return 1; break;
case MDB_LIKE:
return 4; break;
case MDB_ISNULL:
return 12; break;
default:
return 8; break;
}
} else {
switch (sarg->op) {
case MDB_EQUAL:
if (not_all_equal) return 2;
else return 1;
break;
case MDB_LIKE:
return 6; break;
case MDB_ISNULL:
return 12; break;
default:
return 9; break;
}
}
} else {
if (idx->num_keys == 1) {
switch (sarg->op) {
case MDB_EQUAL:
return 2; break;
case MDB_LIKE:
return 5; break;
case MDB_ISNULL:
return 12; break;
default:
return 10; break;
}
} else {
switch (sarg->op) {
case MDB_EQUAL:
if (not_all_equal) return 3;
else return 2;
break;
case MDB_LIKE:
return 7; break;
case MDB_ISNULL:
return 12; break;
default:
return 11; break;
}
}
}
return 0;
}
MdbStrategy
mdb_choose_index(MdbTableDef *table, int *choice)
{
int i;
MdbIndex *idx;
int cost = 0;
int least = 99;
*choice = -1;
for (i=0;i<table->num_idxs;i++) {
idx = g_ptr_array_index (table->indices, i);
cost = mdb_index_compute_cost(table, idx);
//printf("cost for %s is %d\n", idx->name, cost);
if (cost && cost < least) {
least = cost;
*choice = i;
}
}
/* and the winner is: *choice */
if (!least) return MDB_TABLE_SCAN;
return MDB_INDEX_SCAN;
}
void
mdb_index_scan_init(MdbHandle *mdb, MdbTableDef *table)
{
int i;
int use_index=0;
char *s;
if (s=getenv("MDBOPTS")) {
if (!strcmp(s, "use_index")) use_index++;
}
if (use_index && mdb_choose_index(table, &i) == MDB_INDEX_SCAN) {
table->strategy = MDB_INDEX_SCAN;
table->scan_idx = g_ptr_array_index (table->indices, i);
table->chain = g_malloc0(sizeof(MdbIndexChain));
table->mdbidx = mdb_clone_handle(mdb);
mdb_read_pg(table->mdbidx, table->scan_idx->first_pg);
//printf("best index is %s\n",table->scan_idx->name);
}
}
void
mdb_index_scan_free(MdbTableDef *table)
{
if (table->chain) {
g_free(table->chain);
table->chain = NULL;
}
if (table->mdbidx) {
mdb_close(table->mdbidx);
table->mdbidx = NULL;
}
}