1: # include   "../ingres.h"
   2: # include   "../tree.h"
   3: # include   "../symbol.h"
   4: # include   "decomp.h"
   5: 
   6: /*
   7: ** DECOMP1.C
   8: **
   9: **	contains routines associated with setting up
  10: **	detachable 1-variable sub-queries.
  11: **	ptrs to these sq's are kept in the
  12: **	array 'sqlist' declared in the main decomp routine.
  13: **
  14: */
  15: 
  16: pull_sq(tree1, sqlist, locrang, sqrange, buf)
  17: struct querytree    *tree1;
  18: struct querytree    *sqlist[];
  19: int         locrang[];
  20: int         sqrange[];
  21: char            *buf;
  22: {
  23:     register struct querytree   *q, *tree, *r;
  24:     struct querytree        *s;
  25:     int                 anysq, j, badvar;
  26:     extern struct querytree     *makroot();
  27: 
  28:     tree = tree1;
  29: 
  30: #	ifdef xDTR1
  31:     if (tTf(10, 0))
  32:         printf("PULL_SQ:tree=%l\n", tree);
  33: #	endif
  34: 
  35:     anysq = 0;
  36:     for (j = 0; j < MAXRANGE; j++)
  37:         sqlist[j] = 0;
  38: 
  39:     if (((struct qt_root *)tree)->tvarc == 1)
  40:         return;
  41: 
  42:     /* detach all one variable clauses except:
  43: 	** if the target list is one variable and
  44: 	** that variable is disjoint from the other
  45: 	** variables, then don't pull it.
  46: 	**
  47: 	** It will be more efficient to process it
  48: 	** all at once in decompy
  49: 	*/
  50: 
  51:     badvar = 0;
  52:     if (((struct qt_root *)tree)->lvarc == 1)
  53:     {
  54:         badvar = ((struct qt_root *)tree)->lvarm; /* get bit position of var */
  55: 
  56:         /* look for a two variable clause involving badvar */
  57:         for (r = tree->right; r->sym.type != QLEND; r = r->right)
  58:         {
  59:             if (((struct qt_root *)r)->lvarc > 1 && (((struct qt_root *)r)->lvarm & badvar))
  60:             {
  61:                 badvar = 0;
  62:                 break;
  63:             }
  64:         }
  65:     }
  66: #	ifdef xDTR1
  67:     if (tTf(10, 2))
  68:         printf("Detachable clauses: (badvar=%o)\n", badvar);
  69: #	endif
  70:     for (r=tree; r->right->sym.type!=QLEND; )
  71:     {
  72: #		ifdef xDTR1
  73:         if (tTf(10, 3))
  74:             writenod(r);
  75: #		endif
  76:         q = r;
  77:         r = r->right;
  78:         if (((struct qt_root *)r)->lvarc == 1)
  79:         {
  80:             j = bitpos(((struct qt_root *)r)->lvarm);
  81: #			ifdef xDTR1
  82:             if (tTf(10, 4))
  83:             {
  84:                 printf("\nvar=%d,", j);
  85:                 printree(r->left, "clause");
  86:             }
  87: #			endif
  88:             if (((struct qt_root *)r)->lvarm == badvar)
  89:             {
  90: #				ifdef xDTR1
  91:                 if (tTf(10, 5))
  92:                     printf("not detaching \n");
  93: #				endif
  94:                 continue;
  95:             }
  96:             anysq++;
  97: 
  98:             if (!sqlist[j])     /* MAKE ROOT NODE FOR SUBQUERY */
  99:                 sqlist[j] = makroot(buf);
 100:             s = sqlist[j];
 101: 
 102:             /* MODIFY MAIN QUERY */
 103: 
 104:             q->right = r->right;
 105: 
 106:             /* MODIFY `AND` NODE OF DETACHED CLAUSE */
 107: 
 108:             r->right = s->right;
 109:             ((struct qt_root *)r)->rvarm = ((struct qt_root *)s)->rvarm;
 110:             ((struct qt_root *)r)->tvarc = 1;
 111: 
 112:             /* ADD CLAUSE TO SUB-QUERY */
 113: 
 114:             s->right = r;
 115:             ((struct qt_root *)s)->rvarm = ((struct qt_root *)r)->lvarm;
 116:             ((struct qt_root *)s)->tvarc = 1;
 117: 
 118: #			ifdef xDTR1
 119:             if (tTf(10, 6))
 120:                 printree(s, "SQ");
 121: #			endif
 122: 
 123:             r = q;
 124:         }
 125:     }
 126: 
 127:     /* NOW SET UP TARGET LIST FOR EACH SUBQUERY IN SQLIST */
 128: 
 129: #	ifdef xDTR1
 130:     if (tTf(10, 7))
 131:         printf("# sq clauses=%d\n", anysq);
 132: #	endif
 133:     if (anysq)
 134:     {
 135: #		ifdef xDTR1
 136:         if (tTf(10, 8))
 137:             printf("Dfind--\n");
 138: #		endif
 139:         dfind(tree, buf, sqlist);
 140:         mapvar(tree, 1);
 141: 
 142:         /* create the result relations */
 143:         for (j = 0; j < MAXRANGE; j++)
 144:         {
 145:             if (q = sqlist[j])
 146:             {
 147:                 if (q->left->sym.type != TREE)
 148:                 {
 149:                     savrang(locrang, j);
 150:                     sqrange[j] = mak_t_rel(q, "d", -1);
 151:                 }
 152:                 else
 153:                     sqrange[j] = NORESULT;
 154:             }
 155:         }
 156:     }
 157: }
 158: 
 159: dfind(tree1, buf, sqlist)
 160: struct querytree *tree1;
 161: char         *buf;
 162: struct querytree *sqlist[];
 163: {
 164:     register int            varno;
 165:     register struct querytree   *tree, *sq;
 166:     extern struct querytree     *ckvar();
 167: 
 168:     tree = tree1;
 169:     if (!tree)
 170:         return;
 171: #	ifdef xDTR1
 172:     if (tTf(10, 9))
 173:         writenod(tree);
 174: #	endif
 175:     if (tree->sym.type == VAR)
 176:     {
 177:         tree = ckvar(tree);
 178:         varno = ((struct qt_var *)tree)->varno;
 179:         if (sq = sqlist[varno])
 180:             maktl(tree, buf, sq, varno);
 181:         return;
 182:     }
 183: 
 184:     /* IF CURRENT NODE NOT A `VAR` WITH SQ, RECURSE THRU REST OF TREE */
 185: 
 186:     dfind(tree->left, buf, sqlist);
 187:     dfind(tree->right, buf, sqlist);
 188:     return;
 189: }
 190: 
 191: 
 192: maktl(node, buf, sq1, varno)
 193: struct querytree    *node;
 194: char            *buf;
 195: struct querytree    *sq1;
 196: int         varno;
 197: {
 198:     register struct querytree   *resdom, *tree, *sq;
 199:     int             domno, map;
 200:     extern struct querytree     *makresdom(), *copytree();
 201: 
 202:     sq = sq1;
 203:     domno = ((struct qt_var *)node)->attno;
 204: 
 205: #	ifdef xDTR1
 206:     if (tTf(10, 12))
 207:         printf("\tVar=%d,Dom=%d ", varno, domno);
 208: #	endif
 209:     /* CHECK IF NODE ALREADY CREATED FOR THIS DOMAIN */
 210: 
 211:     for (tree = sq->left; tree->sym.type != TREE; tree = tree->left)
 212:         if (((struct qt_var *)tree->right)->attno == domno)
 213:         {
 214: #			ifdef xDTR1
 215:             if (tTf(10, 13))
 216:                 printf("Domain found\n");
 217: #			endif
 218:             return;
 219:         }
 220: 
 221:     /* create a new resdom for domain */
 222: 
 223:     resdom = makresdom(buf, node);
 224:     *resdom->sym.value = sq->left->sym.type == TREE? 1:
 225:                     *sq->left->sym.value + 1;
 226:     /* resdom->right is a copy of the var node in order to
 227: 	** protect against tempvar() changing the var node.
 228: 	*/
 229:     resdom->left = sq->left;
 230:     resdom->right = copytree(node, buf);
 231: 
 232: 
 233:     /* update ROOT node if necessary */
 234: 
 235:     sq->left = resdom;
 236:     map = 1 << varno;
 237:     if (!(((struct qt_root *)sq)->lvarm & map))
 238:     {
 239:         /* var not currently in tl */
 240:         ((struct qt_root *)sq)->lvarm |= map;
 241:         ((struct qt_root *)sq)->lvarc++;
 242: 
 243:         /* if var is not in qualification then update total count */
 244:         if (!(((struct qt_root *)sq)->rvarm & map))
 245:             ((struct qt_root *)sq)->tvarc++;
 246: #		ifdef xDTR1
 247:         if (tTf(10, 15))
 248:         {
 249:             printf("new root ");
 250:             writenod(sq);
 251:         }
 252: #		endif
 253:     }
 254: 
 255: #	ifdef xDTR1
 256:     if (tTf(10, 14))
 257:     {
 258:         printf("new dom ");
 259:         writenod(resdom);
 260:     }
 261: #	endif
 262:     return;
 263: }

Defined functions

dfind defined in line 159; used 5 times
maktl defined in line 192; used 1 times
pull_sq defined in line 16; used 2 times
Last modified: 1995-04-14
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