4.3BSD - /usr/ingres/source/qrymod/integrity.c

   1: # include   <ingres.h>
   2: # include   <aux.h>
   3: # include   <catalog.h>
   4: # include   <access.h>
   5: # include   <tree.h>
   6: # include   <symbol.h>
   7: # include   "qrymod.h"
   8: # include   <sccs.h>
   9: 
  10: SCCSID(@(#)integrity.c	8.3	5/12/85)
  11: 
  12: /*
  13: **  INTEGRITY.C -- Integrity Constraint Processor
  14: **
  15: **	This module contains the integrity constraint processor.  This
  16: **	processor modifies the query to add integrity constraints.
  17: **
  18: **	Currently only single-variable aggregate-free constraints are
  19: **	handled.  Thus the algorithm is reduced to scanning the tree
  20: **	for each variable modified and appending the constraints for
  21: **	that variable to the tree.
  22: **
  23: **	Parameters:
  24: **		none
  25: **
  26: **	Returns:
  27: **		The root of the modified tree.
  28: **
  29: **	Side Effects:
  30: **		Much relation I/O.
  31: **		Modifies the tree in place, so the previous one is
  32: **			lost.
  33: **
  34: **	Trace Flags:
  35: **		40 -> 49
  36: */
  37: 
  38: extern DESC Intdes;
  39: 
  40: QTREE *
  41: integrity(root)
  42: QTREE   *root;
  43: {
  44:     register QTREE      *r;
  45:     int         dset[8];
  46:     register QTREE      *p;
  47:     register int        i;
  48:     auto QTREE      *iqual;
  49:     struct integrity    inttup, intkey;
  50:     struct tup_id       hitid, lotid;
  51:     extern QTREE        *gettree();
  52:     extern QTREE        *norml();
  53: 
  54: #	ifdef xQTR1
  55:     tTfp(40, -1, "\n->INTEGRITY\n");
  56: #	endif
  57: 
  58:     r = root;
  59: 
  60:     /*
  61: 	**  Check to see if we should apply the integrity
  62: 	**  algorithm.
  63: 	**
  64: 	**  This means checking to insure that we have an update
  65: 	**  and seeing if any integrity constraints apply.
  66: 	*/
  67: 
  68:     if (Qt.qt_qmode == mdRETR || Qt.qt_qmode == mdRET_UNI ||
  69:         (Qt.qt_rangev[Qt.qt_resvar].rngvdesc->reldum.relstat & S_INTEG) == 0)
  70:     {
  71: #		ifdef xQTR2
  72:         tTfp(40, 0, "->INTEGRITY: no integ\n");
  73: #		endif
  74:         return(r);
  75:     }
  76: 
  77:     /*
  78: 	**  Create a set of the domains updated in this query.
  79: 	*/
  80: 
  81:     for (i = 0; i < 8; i++)
  82:         dset[i] = 0;
  83:     for (p = r->left; p != NULL && p->sym.type != TREE; p = p->left)
  84:     {
  85: #		ifdef xQTR3
  86:         if (p->sym.type != RESDOM)
  87:             syserr("integrity: RESDOM %d", p->sym.type);
  88: #		endif
  89:         lsetbit(p->sym.value.sym_resdom.resno, dset);
  90:     }
  91: 
  92: #	ifdef xQTR3
  93:     if (p == NULL)
  94:         syserr("integrity: NULL LHS");
  95: #	endif
  96: #	ifdef xQTR1
  97:     if (tTf(40, 1))
  98:         pr_set(dset, "dset");
  99: #	endif
 100: 
 101:     /*
 102: 	**  Scan integrity catalog for possible tuples.  If found,
 103: 	**  include them in the integrity qualification.
 104: 	*/
 105: 
 106:     iqual = NULL;
 107:     opencatalog("integrities", OR_READ);
 108:     setkey(&Intdes, &intkey, Qt.qt_rangev[Qt.qt_resvar].rngvdesc->reldum.relid, INTRELID);
 109:     setkey(&Intdes, &intkey, Qt.qt_rangev[Qt.qt_resvar].rngvdesc->reldum.relowner, INTRELOWNER);
 110:     find(&Intdes, EXACTKEY, &lotid, &hitid, &intkey);
 111: 
 112:     while ((i = get(&Intdes, &lotid, &hitid, &inttup, TRUE)) == 0)
 113:     {
 114:         if (kcompare(&Intdes, &intkey, &inttup) != 0)
 115:             continue;
 116: 
 117: #		ifdef xQTR1
 118:         if (tTf(40, 2))
 119:             printup(&Intdes, &inttup);
 120: #		endif
 121: 
 122:         /* check for some domain set overlap */
 123:         for (i = 0; i < 8; i++)
 124:             if ((dset[i] & inttup.intdomset[i]) != 0)
 125:                 break;
 126:         if (i >= 8)
 127:             continue;
 128: 
 129:         /* some domain matches, include in integrity qual */
 130:         i = Qt.qt_resvar;
 131:         p = gettree(Qt.qt_rangev[i].rngvdesc->reldum.relid,
 132:                 Qt.qt_rangev[i].rngvdesc->reldum.relowner,
 133:                 mdINTEG, inttup.inttree, FALSE);
 134: #		ifdef xQTR1
 135:         if (tTf(40, 3))
 136:             treepr(p, "int_qual");
 137: #		endif
 138: 
 139:         /* trim off (null) target list */
 140:         p = p->right;
 141: 
 142:         /* merge the 'integrity' var into the Qt.qt_resvar */
 143:         i = inttup.intresvar;
 144:         if (Qt.qt_remap[i] >= 0)
 145:             i = Qt.qt_remap[i];
 146:         mergevar(i, Qt.qt_resvar, p);
 147: 
 148:         /* add to integrity qual */
 149:         if (iqual == NULL)
 150:             iqual = p;
 151:         else
 152:             appqual(p, iqual);
 153:     }
 154:     if (i < 0)
 155:         syserr("integrity: get %d", i);
 156: 
 157:     /*
 158: 	**  Clean up the integrity qualification so that it will merge
 159: 	**  nicely into the tree, and then append it to the user's
 160: 	**  qualification.
 161: 	*/
 162: 
 163:     if (iqual != NULL)
 164:     {
 165:         /* replace VAR nodes by corresponding user afcn */
 166:         subsvars(&iqual, Qt.qt_resvar, r->left, Qt.qt_qmode);
 167: 
 168:         /* append to tree and normalize */
 169:         appqual(iqual, r);
 170: #		ifdef xQTR3
 171:         if (tTf(40, 8))
 172:             treepr(r, "Unnormalized tree");
 173: #		endif
 174:         r->right = norml(trimqlend(r->right));
 175:     }
 176: 
 177: #	ifdef xQTR1
 178:     if (tTf(40, 15))
 179:         treepr(r, "INTEGRITY->");
 180: #	endif
 181: 
 182:     return (r);
 183: }

Defined functions