src/storage/JoinTableImpl.cxx

   1 /***************************************************************************
   2  *   Copyright (C) 2007 by www.databasecache.com                           *
   3  *   Contact: praba_tuty@databasecache.com                                 *
   4  *                                                                         *
   5  *   This program is free software; you can redistribute it and/or modify  *
   6  *   it under the terms of the GNU General Public License as published by  *
   7  *   the Free Software Foundation; either version 2 of the License, or     *
   8  *   (at your option) any later version.                                   *
   9  *                                                                         *
  10  *   This program is distributed in the hope that it will be useful,       *
  11  *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
  13  *   GNU General Public License for more details.                          *
  14  *                                                                         *
  15   ***************************************************************************/
  16 #include<Debug.h>
  17 #include<Table.h>
  18 #include<TableImpl.h>
  19 #include<JoinTableImpl.h>
  20 #include<PredicateImpl.h>
  21
  22 JoinTableImpl::JoinTableImpl()
  23 {
  24     isNestedLoop= true;
  25     pred = NULL;
  26     curTuple = NULL;
  27     leftTableHdl = NULL;
  28     rightTableHdl = NULL;
  29 }
  30 JoinTableImpl::~JoinTableImpl()
  31 {
  32     close();
  33 }
  34 /* moved to Table class
  35  * shall be removed
  36 void JoinTableImpl::getFieldNameAlone(char *fname, char *name) {
  37     bool dotFound= false;
  38     char *fullname = fname;
  39     while(*fullname != '\0')
  40     {
  41         if (*fullname == '.') { dotFound = true;  break; }
  42         fullname++;
  43     }
  44     if (dotFound) strcpy(name, ++fullname); else strcpy(name, fname);
  45
  46 }
  47 void JoinTableImpl::getTableNameAlone(char *fname, char *name) {
  48     strcpy(name, fname);
  49     while(*name != '\0')
  50     {
  51         if (*name == '.') { *name='\0';  break; }
  52         name++;
  53     }
  54     return;
  55 }
  56 */
  57 DbRetVal JoinTableImpl::bindFld(const char *fldname, void *val)
  58 {
  59     FieldInfo *info = new FieldInfo();
  60     char tableName[IDENTIFIER_LENGTH];
  61     char fieldName[IDENTIFIER_LENGTH];
  62     getTableNameAlone((char*)fldname, tableName);
  63     getFieldNameAlone((char*)fldname, fieldName);
  64     ListIterator iter = projList.getIterator();
  65     JoinProjFieldInfo  *elem;
  66     while (iter.hasElement())
  67     {
  68         elem = (JoinProjFieldInfo*) iter.nextElement();
  69         if (strcmp(elem->fieldName, fieldName)==0 &&
  70             strcmp(elem->tableName, tableName) ==0)
  71         {
  72             printError(ErrBadCall, "Field already binded %s\n", fldname);
  73             delete info;
  74             return ErrBadCall;
  75         }
  76     }
  77     JoinProjFieldInfo *def = new JoinProjFieldInfo();
  78     strcpy(def->tableName, tableName);
  79     strcpy(def->fieldName, fieldName);
  80     strcpy(def->tabFieldName, fldname);
  81     def->appBuf = val;
  82     getFieldInfo(fldname, info);
  83     def->bindBuf = AllDataType::alloc(info->type, info->length);
  84     if (availableLeft)
  85         leftTableHdl->bindFld(fldname, def->bindBuf);
  86     else
  87         rightTableHdl->bindFld(fldname, def->bindBuf);
  88     def->type = info->type;
  89     def->length= info->length;
  90     projList.append(def);
  91     delete info;
  92     return OK;
  93 }
  94
  95 DbRetVal JoinTableImpl::optimize()
  96 {
  97     PredicateImpl* predImpl = (PredicateImpl*) pred;
  98     if (NULL != predImpl && !predImpl->isNotOrInvolved())
  99     {
 100         //printf("not or or not involved\n");
 101         PredicateImpl *tblPred = NULL;
 102         bool isPushed = false;
 103         while (true)
 104         {
 105             tblPred = predImpl->getTablePredicate();
 106             if (NULL == tblPred) break;
 107             if (pred == tblPred)
 108             {
 109                 pred = NULL;
 110                 isPushed = pushPredicate(tblPred);
 111                 if (!isPushed)
 112                 {
 113                     //printf("optimizer could not push table predicate\n");
 114                 }
 115                 break;
 116             }
 117             isPushed = pushPredicate(tblPred);
 118             if (!isPushed)
 119             {
 120                 //printf("optimizer could not push table predicate\n");
 121             }
 122         }
 123         while (true)
 124         {
 125             tblPred = predImpl->getJoinPredicate();
 126             if (pred == tblPred)
 127             {
 128                 break;
 129             }
 130             if (NULL == tblPred) break;
 131             isPushed = pushPredicate(tblPred);
 132             if (!isPushed)
 133             {
 134                 //printf("optimizer could not push join predicate\n");
 135             }
 136         }
 137     }
 138     if (pred != NULL)
 139     {
 140         //push predicates leave the predicate nodes empty
 141         //here we remove all the unnecessary nodes
 142         predImpl = (PredicateImpl*) pred;
 143         predImpl->removeIfNotNecessary();
 144         PredicateImpl *p = predImpl->getIfOneSidedPredicate();
 145         if (NULL != p)
 146         {
 147             //TODO::fix this leak below..it dumps core if uncommented
 148             //delete pred;
 149             pred = p;
 150             predImpl = p;
 151         }
 152         if (predImpl->isDummyPredicate())
 153         {
 154             //TODO::fix this leak below..it dumps core if uncommented
 155             //delete pred;
 156             pred = NULL;
 157         }
 158     }
 159     DbRetVal rv = leftTableHdl->optimize();
 160     if (OK != rv) {
 161         printError(ErrUnknown, "Left handle optimize failed");
 162         return rv;
 163     }
 164     rv = rightTableHdl->optimize();
 165     if (OK != rv) {
 166         printError(ErrUnknown, "Left handle optimize failed");
 167         return rv;
 168     }
 169     optimizeRestrict();
 170     return OK;
 171 }
 172 void JoinTableImpl::optimizeRestrict()
 173 {
 174     ScanType lType = leftTableHdl->getScanType();
 175     ScanType rType = rightTableHdl->getScanType();
 176     bool interChange = false;
 177     if (lType == fullTableScan && rType != fullTableScan)  interChange = true;
 178     else if (lType != hashIndexScan  && rType == treeIndexScan) interChange=true;
 179     /*
 180     if (interChange) {
 181        Table *tmp = leftTableHdl;
 182        leftTableHdl=rightTableHdl;
 183        rightTableHdl = tmp;
 184     }*/
 185
 186     //get the predicate with right table handle name
 187     //rightTableHdl->getIndexType();
 188     return;
 189 }
 190 ScanType JoinTableImpl::getScanType()
 191 {
 192     ScanType lType = leftTableHdl->getScanType();
 193     ScanType rType = rightTableHdl->getScanType();
 194     if (lType == hashIndexScan || rType == hashIndexScan) return hashIndexScan;
 195     if (lType == treeIndexScan || rType == treeIndexScan) return treeIndexScan;
 196     return fullTableScan;
 197 }
 198
 199 void JoinTableImpl::printPlan(int space)
 200 {
 201     char spaceBuf[IDENTIFIER_LENGTH];
 202     memset(spaceBuf, 32, IDENTIFIER_LENGTH);
 203     spaceBuf[space] = '\0';
 204     PredicateImpl* predImpl = (PredicateImpl*) pred;
 205     printf("%s <JOIN-NODE>\n", spaceBuf);
 206     if (predImpl) predImpl->print(space);
 207     printf("%s <LEFT>\n", spaceBuf);
 208     leftTableHdl->printPlan(space+2);
 209     printf("%s </LEFT>\n", spaceBuf);
 210     printf("%s <RIGHT>\n", spaceBuf);
 211     rightTableHdl->printPlan(space+2);
 212     printf("%s </RIGHT>\n", spaceBuf);
 213     printf("%s </JOIN-NODE>\n", spaceBuf);
 214 }
 215 DbRetVal JoinTableImpl::execute()
 216 {
 217     PredicateImpl* predImpl = (PredicateImpl*) pred;
 218     isNestedLoop = true;
 219     if (pred) predImpl->setProjectionList(&projList);
 220     //push the table scan predicates
 221     optimize();
 222     leftTableHdl->execute();
 223     leftTableHdl->fetch();
 224     rightTableHdl->execute();
 225     //TODO
 226     //if join condition is not set then do nl
 227     //if it is inner join, hen do nl
 228     //nl cannot be done for outer join
 229     return OK;
 230 }
 231
 232 void* JoinTableImpl::fetch()
 233 {
 234     PredicateImpl* predImpl = (PredicateImpl*) pred;
 235     DbRetVal rv = OK;
 236     if (isNestedLoop)
 237     {
 238         void *rec = rightTableHdl->fetch();
 239         if (rec==NULL)
 240         {
 241             rightTableHdl->closeScan();
 242             rec = leftTableHdl->fetch();
 243             if (rec == NULL) return NULL;
 244             rightTableHdl->execute();
 245             rec = rightTableHdl->fetch();
 246             if (rec == NULL) return NULL;
 247             bool result = true;
 248             while (true) {
 249                 if (pred) rv = predImpl->evaluate(result);
 250                 if ( OK != rv) return NULL;
 251                 if (result) break;
 252                 rec = rightTableHdl->fetch();
 253                 if (rec == NULL) return fetch();
 254             }
 255             copyValuesToBindBuffer(NULL);
 256             return rec;
 257         }
 258         else {
 259             bool result = true;
 260             while (true) {
 261                 if (pred) rv = predImpl->evaluate(result);
 262                 if ( rv !=OK) return NULL;
 263                 if (result) break;
 264                 rec = rightTableHdl->fetch();
 265                 if (rec == NULL) return fetch();
 266             }
 267             copyValuesToBindBuffer(NULL);
 268             return rec;
 269         }
 270
 271     }
 272     return NULL;
 273 }
 274 void* JoinTableImpl::fetch(DbRetVal &rv)
 275 {
 276     rv = OK;
 277     return fetch();
 278 }
 279
 280 void* JoinTableImpl::fetchNoBind()
 281 {
 282     return NULL;
 283 }
 284
 285 void* JoinTableImpl::fetchNoBind(DbRetVal &rv)
 286 {
 287     rv = OK;
 288     return fetchNoBind();
 289 }
 290
 291 DbRetVal JoinTableImpl::copyValuesToBindBuffer(void *elem)
 292 {
 293     //Iterate through the bind list and copy the value here
 294     ListIterator fIter = projList.getIterator();
 295     JoinProjFieldInfo  *def;
 296     while (fIter.hasElement())
 297     {
 298         def = (JoinProjFieldInfo*) fIter.nextElement();
 299         if (NULL != def->appBuf) {
 300             AllDataType::copyVal(def->appBuf, def->bindBuf, def->type, def->length);
 301         }
 302     }
 303     return OK;
 304 }
 305 DbRetVal JoinTableImpl::getFieldInfo(const char* fldname, FieldInfo *&info)
 306 {
 307     DbRetVal retCode = OK;
 308     retCode = leftTableHdl->getFieldInfo(fldname, info);
 309     if (retCode ==OK)
 310     {
 311         availableLeft= true;
 312         return OK;
 313     }
 314     retCode = rightTableHdl->getFieldInfo(fldname, info);
 315     if (retCode ==OK)
 316     {
 317         availableLeft= false;
 318         return OK;
 319     }
 320     return ErrNotExists;
 321 }
 322
 323 long JoinTableImpl::numTuples()
 324 {
 325     return 0;
 326 }
 327 DbRetVal JoinTableImpl::closeScan()
 328 {
 329     if (leftTableHdl) leftTableHdl->closeScan();
 330     if (rightTableHdl) rightTableHdl->closeScan();
 331     return OK;
 332
 333 }
 334
 335 DbRetVal JoinTableImpl::close()
 336 {
 337     if (leftTableHdl) { leftTableHdl->close(); leftTableHdl = NULL; }
 338     if (rightTableHdl) { rightTableHdl->close(); rightTableHdl = NULL; }
 339     closeScan();
 340     ListIterator iter = projList.getIterator();
 341     JoinProjFieldInfo  *elem;
 342     while (iter.hasElement())
 343     {
 344         elem = (JoinProjFieldInfo*) iter.nextElement();
 345         free(elem->bindBuf);
 346         delete elem;
 347     }
 348     projList.reset();
 349     return OK;
 350 }
 351 void* JoinTableImpl::getBindFldAddr(const char *name)
 352 {
 353     printf("PRABA::join getBindFldAddr not implemented\n");
 354     return NULL;
 355 }
 356 List JoinTableImpl::getFieldNameList()
 357 {
 358     List fldNameList;
 359
 360     List leftList = leftTableHdl->getFieldNameList();
 361     ListIterator lIter = leftList.getIterator();
 362     while (lIter.hasElement())
 363     {
 364         Identifier *elem = (Identifier*) lIter.nextElement();
 365         fldNameList.append(elem);
 366     }
 367
 368     List rightList = rightTableHdl->getFieldNameList();
 369     ListIterator rIter = rightList.getIterator();
 370     while (rIter.hasElement())
 371     {
 372         Identifier *elem = (Identifier*) rIter.nextElement();
 373         fldNameList.append(elem);
 374     }
 375     return fldNameList;
 376 }
 377 bool JoinTableImpl::isTableInvolved(char *tableName)
 378 {
 379     //printf("isTableInvolved called in join for %s\n", tableName);
 380     bool isInvolved = leftTableHdl->isTableInvolved(tableName);
 381     if (isInvolved) return true;
 382     isInvolved = rightTableHdl->isTableInvolved(tableName);
 383     return isInvolved;
 384 }
 385 void* JoinTableImpl::getBindedBuf(char* tName, char* fName)
 386 {
 387     ListIterator iter = projList.getIterator();
 388     JoinProjFieldInfo  *elem;
 389     while (iter.hasElement())
 390     {
 391         elem = (JoinProjFieldInfo*) iter.nextElement();
 392         if (strcmp(elem->fieldName, fName)==0 &&
 393             strcmp(elem->tableName, tName) ==0)
 394         {
 395             return elem->bindBuf;
 396         }
 397     }
 398     return NULL;
 399 }
 400 bool JoinTableImpl::pushPredicate(Predicate *pr)
 401 {
 402     //printf("PRABA::pushPredicate called\n");
 403     PredicateImpl *pImpl = (PredicateImpl*) pr;
 404     bool pushed = leftTableHdl->pushPredicate(pr);
 405     if (!pushed)
 406     {
 407         pushed = rightTableHdl->pushPredicate(pr);
 408     }
 409     if (!pushed)
 410     {
 411         //printf("PRABA::unable to push the predicate\n");
 412         //TODO::check if needs to be placed here
 413         char *lTbl = leftTableHdl->getName();
 414         char *rTbl = rightTableHdl->getName();
 415         char fullName[IDENTIFIER_LENGTH];
 416         char lTabName[IDENTIFIER_LENGTH];
 417         char rTabName[IDENTIFIER_LENGTH];
 418         char lFldName[IDENTIFIER_LENGTH];
 419         char rFldName[IDENTIFIER_LENGTH];
 420         strcpy(fullName, pImpl->getFldName1());
 421         Table::getTableNameAlone(fullName, lTabName);
 422         Table::getFieldNameAlone(fullName, lFldName);
 423         strcpy(fullName, pImpl->getFldName2());
 424         Table::getTableNameAlone(fullName, rTabName);
 425         Table::getFieldNameAlone(fullName, rFldName);
 426
 427         if (NULL != lTbl && NULL != rTbl)
 428         {
 429             //both size TableImpl handles are there
 430             if (0 == strcmp(lTbl, lTabName) || 0 == strcmp(lTbl, rTabName))
 431             {
 432                 if (0 == strcmp(rTbl, lTabName) || 0 == strcmp(rTbl, rTabName))
 433                 {
 434                     //printf("PRABA::pushed join predicate here1\n");
 435                     //PRABA::START
 436                     ComparisionOp op = pImpl->getCompOp();
 437                     if (strcmp(rTbl, rTabName) ==0)
 438                     {
 439                         //bool ind = rightTableHdl->hasIndex(rFldName);
 440                         //if (ind) {
 441                             void *buf = getBindedBuf(lTabName, lFldName);
 442                             rightTableHdl->addPredicate(rFldName, op, buf);
 443                             pImpl->setDontEvaluate();
 444                         //}
 445                     }else if (strcmp(rTbl, lTabName) ==0)
 446                     {
 447                         //bool ind = rightTableHdl->hasIndex(lFldName);
 448                         //if (ind) {
 449                             void *buf = getBindedBuf(rTabName, rFldName);
 450                             rightTableHdl->addPredicate(lFldName, op, buf);
 451                             pImpl->setDontEvaluate();
 452                         //}
 453                     }
 454                     //PRABA::END
 455                     setPredicate(pr);
 456                     pushed = true;
 457                 }
 458             }
 459         }else{
 460             if(isTableInvolved(lTabName) && isTableInvolved(rTabName))
 461             {
 462                 //printf("PRABA::pushed join predicate here2\n");
 463                     //PRABA::START
 464                     ComparisionOp op = pImpl->getCompOp();
 465                     if (strcmp(rTbl, rTabName) ==0)
 466                     {
 467                         //bool ind = rightTableHdl->hasIndex(rFldName);
 468                         //if (ind) {
 469                             void *buf = getBindedBuf(lTabName, lFldName);
 470                             rightTableHdl->addPredicate(rFldName, op, buf);
 471                             pImpl->setDontEvaluate();
 472                         //}
 473                     }else if (strcmp(rTbl, lTabName) ==0)
 474                     {
 475                         //bool ind = rightTableHdl->hasIndex(lFldName);
 476                         //if (ind) {
 477                             void *buf = getBindedBuf(rTabName, rFldName);
 478                             rightTableHdl->addPredicate(lFldName, op, buf);
 479                             pImpl->setDontEvaluate();
 480                         //}
 481                     }
 482                     //PRABA::END
 483                 setPredicate(pr);
 484                 pushed = true;
 485             }
 486         }
 487     }
 488     return pushed;
 489 }
 490 void JoinTableImpl::setPredicate(Predicate *pr)
 491 {
 492     if (NULL == pred) { pred = pr; return; }
 493     Predicate *curPred = pred;
 494     PredicateImpl *newPred = new PredicateImpl();
 495     newPred->setTerm(curPred, OpAnd, pr);
 496     newPred->setProjectionList(&projList);
 497     pred = newPred;
 498     return;
 499 }