1/*
2** 2013-11-12
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12**
13** This file contains structure and macro definitions for the query
14** planner logic in "where.c". These definitions are broken out into
15** a separate source file for easier editing.
16*/
17#ifndef SQLITE_WHEREINT_H
18#define SQLITE_WHEREINT_H
19
20
21/* Forward references
22*/
23typedef struct WhereClause WhereClause;
24typedef struct WhereMaskSet WhereMaskSet;
25typedef struct WhereOrInfo WhereOrInfo;
26typedef struct WhereAndInfo WhereAndInfo;
27typedef struct WhereLevel WhereLevel;
28typedef struct WhereLoop WhereLoop;
29typedef struct WherePath WherePath;
30typedef struct WhereTerm WhereTerm;
31typedef struct WhereLoopBuilder WhereLoopBuilder;
32typedef struct WhereScan WhereScan;
33typedef struct WhereOrCost WhereOrCost;
34typedef struct WhereOrSet WhereOrSet;
35typedef struct WhereMemBlock WhereMemBlock;
36typedef struct WhereRightJoin WhereRightJoin;
37
38/*
39** This object is a header on a block of allocated memory that will be
40** automatically freed when its WInfo oject is destructed.
41*/
42struct WhereMemBlock {
43 WhereMemBlock *pNext; /* Next block in the chain */
44 u64 sz; /* Bytes of space */
45};
46
47/*
48** Extra information attached to a WhereLevel that is a RIGHT JOIN.
49*/
50struct WhereRightJoin {
51 int iMatch; /* Cursor used to determine prior matched rows */
52 int regBloom; /* Bloom filter for iRJMatch */
53 int regReturn; /* Return register for the interior subroutine */
54 int addrSubrtn; /* Starting address for the interior subroutine */
55 int endSubrtn; /* The last opcode in the interior subroutine */
56};
57
58/*
59** This object contains information needed to implement a single nested
60** loop in WHERE clause.
61**
62** Contrast this object with WhereLoop. This object describes the
63** implementation of the loop. WhereLoop describes the algorithm.
64** This object contains a pointer to the WhereLoop algorithm as one of
65** its elements.
66**
67** The WhereInfo object contains a single instance of this object for
68** each term in the FROM clause (which is to say, for each of the
69** nested loops as implemented). The order of WhereLevel objects determines
70** the loop nested order, with WhereInfo.a[0] being the outer loop and
71** WhereInfo.a[WhereInfo.nLevel-1] being the inner loop.
72*/
73struct WhereLevel {
74 int iLeftJoin; /* Memory cell used to implement LEFT OUTER JOIN */
75 int iTabCur; /* The VDBE cursor used to access the table */
76 int iIdxCur; /* The VDBE cursor used to access pIdx */
77 int addrBrk; /* Jump here to break out of the loop */
78 int addrNxt; /* Jump here to start the next IN combination */
79 int addrSkip; /* Jump here for next iteration of skip-scan */
80 int addrCont; /* Jump here to continue with the next loop cycle */
81 int addrFirst; /* First instruction of interior of the loop */
82 int addrBody; /* Beginning of the body of this loop */
83 int regBignull; /* big-null flag reg. True if a NULL-scan is needed */
84 int addrBignull; /* Jump here for next part of big-null scan */
85#ifndef SQLITE_LIKE_DOESNT_MATCH_BLOBS
86 u32 iLikeRepCntr; /* LIKE range processing counter register (times 2) */
87 int addrLikeRep; /* LIKE range processing address */
88#endif
89 int regFilter; /* Bloom filter */
90 WhereRightJoin *pRJ; /* Extra information for RIGHT JOIN */
91 u8 iFrom; /* Which entry in the FROM clause */
92 u8 op, p3, p5; /* Opcode, P3 & P5 of the opcode that ends the loop */
93 int p1, p2; /* Operands of the opcode used to end the loop */
94 union { /* Information that depends on pWLoop->wsFlags */
95 struct {
96 int nIn; /* Number of entries in aInLoop[] */
97 struct InLoop {
98 int iCur; /* The VDBE cursor used by this IN operator */
99 int addrInTop; /* Top of the IN loop */
100 int iBase; /* Base register of multi-key index record */
101 int nPrefix; /* Number of prior entires in the key */
102 u8 eEndLoopOp; /* IN Loop terminator. OP_Next or OP_Prev */
103 } *aInLoop; /* Information about each nested IN operator */
104 } in; /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */
105 Index *pCoveringIdx; /* Possible covering index for WHERE_MULTI_OR */
106 } u;
107 struct WhereLoop *pWLoop; /* The selected WhereLoop object */
108 Bitmask notReady; /* FROM entries not usable at this level */
109#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
110 int addrVisit; /* Address at which row is visited */
111#endif
112};
113
114/*
115** Each instance of this object represents an algorithm for evaluating one
116** term of a join. Every term of the FROM clause will have at least
117** one corresponding WhereLoop object (unless INDEXED BY constraints
118** prevent a query solution - which is an error) and many terms of the
119** FROM clause will have multiple WhereLoop objects, each describing a
120** potential way of implementing that FROM-clause term, together with
121** dependencies and cost estimates for using the chosen algorithm.
122**
123** Query planning consists of building up a collection of these WhereLoop
124** objects, then computing a particular sequence of WhereLoop objects, with
125** one WhereLoop object per FROM clause term, that satisfy all dependencies
126** and that minimize the overall cost.
127*/
128struct WhereLoop {
129 Bitmask prereq; /* Bitmask of other loops that must run first */
130 Bitmask maskSelf; /* Bitmask identifying table iTab */
131#ifdef SQLITE_DEBUG
132 char cId; /* Symbolic ID of this loop for debugging use */
133#endif
134 u8 iTab; /* Position in FROM clause of table for this loop */
135 u8 iSortIdx; /* Sorting index number. 0==None */
136 LogEst rSetup; /* One-time setup cost (ex: create transient index) */
137 LogEst rRun; /* Cost of running each loop */
138 LogEst nOut; /* Estimated number of output rows */
139 union {
140 struct { /* Information for internal btree tables */
141 u16 nEq; /* Number of equality constraints */
142 u16 nBtm; /* Size of BTM vector */
143 u16 nTop; /* Size of TOP vector */
144 u16 nDistinctCol; /* Index columns used to sort for DISTINCT */
145 Index *pIndex; /* Index used, or NULL */
146 } btree;
147 struct { /* Information for virtual tables */
148 int idxNum; /* Index number */
149 u32 needFree : 1; /* True if sqlite3_free(idxStr) is needed */
150 u32 bOmitOffset : 1; /* True to let virtual table handle offset */
151 i8 isOrdered; /* True if satisfies ORDER BY */
152 u16 omitMask; /* Terms that may be omitted */
153 char *idxStr; /* Index identifier string */
154 u32 mHandleIn; /* Terms to handle as IN(...) instead of == */
155 } vtab;
156 } u;
157 u32 wsFlags; /* WHERE_* flags describing the plan */
158 u16 nLTerm; /* Number of entries in aLTerm[] */
159 u16 nSkip; /* Number of NULL aLTerm[] entries */
160 /**** whereLoopXfer() copies fields above ***********************/
161# define WHERE_LOOP_XFER_SZ offsetof(WhereLoop,nLSlot)
162 u16 nLSlot; /* Number of slots allocated for aLTerm[] */
163 WhereTerm **aLTerm; /* WhereTerms used */
164 WhereLoop *pNextLoop; /* Next WhereLoop object in the WhereClause */
165 WhereTerm *aLTermSpace[3]; /* Initial aLTerm[] space */
166};
167
168/* This object holds the prerequisites and the cost of running a
169** subquery on one operand of an OR operator in the WHERE clause.
170** See WhereOrSet for additional information
171*/
172struct WhereOrCost {
173 Bitmask prereq; /* Prerequisites */
174 LogEst rRun; /* Cost of running this subquery */
175 LogEst nOut; /* Number of outputs for this subquery */
176};
177
178/* The WhereOrSet object holds a set of possible WhereOrCosts that
179** correspond to the subquery(s) of OR-clause processing. Only the
180** best N_OR_COST elements are retained.
181*/
182#define N_OR_COST 3
183struct WhereOrSet {
184 u16 n; /* Number of valid a[] entries */
185 WhereOrCost a[N_OR_COST]; /* Set of best costs */
186};
187
188/*
189** Each instance of this object holds a sequence of WhereLoop objects
190** that implement some or all of a query plan.
191**
192** Think of each WhereLoop object as a node in a graph with arcs
193** showing dependencies and costs for travelling between nodes. (That is
194** not a completely accurate description because WhereLoop costs are a
195** vector, not a scalar, and because dependencies are many-to-one, not
196** one-to-one as are graph nodes. But it is a useful visualization aid.)
197** Then a WherePath object is a path through the graph that visits some
198** or all of the WhereLoop objects once.
199**
200** The "solver" works by creating the N best WherePath objects of length
201** 1. Then using those as a basis to compute the N best WherePath objects
202** of length 2. And so forth until the length of WherePaths equals the
203** number of nodes in the FROM clause. The best (lowest cost) WherePath
204** at the end is the chosen query plan.
205*/
206struct WherePath {
207 Bitmask maskLoop; /* Bitmask of all WhereLoop objects in this path */
208 Bitmask revLoop; /* aLoop[]s that should be reversed for ORDER BY */
209 LogEst nRow; /* Estimated number of rows generated by this path */
210 LogEst rCost; /* Total cost of this path */
211 LogEst rUnsorted; /* Total cost of this path ignoring sorting costs */
212 i8 isOrdered; /* No. of ORDER BY terms satisfied. -1 for unknown */
213 WhereLoop **aLoop; /* Array of WhereLoop objects implementing this path */
214};
215
216/*
217** The query generator uses an array of instances of this structure to
218** help it analyze the subexpressions of the WHERE clause. Each WHERE
219** clause subexpression is separated from the others by AND operators,
220** usually, or sometimes subexpressions separated by OR.
221**
222** All WhereTerms are collected into a single WhereClause structure.
223** The following identity holds:
224**
225** WhereTerm.pWC->a[WhereTerm.idx] == WhereTerm
226**
227** When a term is of the form:
228**
229** X <op> <expr>
230**
231** where X is a column name and <op> is one of certain operators,
232** then WhereTerm.leftCursor and WhereTerm.u.leftColumn record the
233** cursor number and column number for X. WhereTerm.eOperator records
234** the <op> using a bitmask encoding defined by WO_xxx below. The
235** use of a bitmask encoding for the operator allows us to search
236** quickly for terms that match any of several different operators.
237**
238** A WhereTerm might also be two or more subterms connected by OR:
239**
240** (t1.X <op> <expr>) OR (t1.Y <op> <expr>) OR ....
241**
242** In this second case, wtFlag has the TERM_ORINFO bit set and eOperator==WO_OR
243** and the WhereTerm.u.pOrInfo field points to auxiliary information that
244** is collected about the OR clause.
245**
246** If a term in the WHERE clause does not match either of the two previous
247** categories, then eOperator==0. The WhereTerm.pExpr field is still set
248** to the original subexpression content and wtFlags is set up appropriately
249** but no other fields in the WhereTerm object are meaningful.
250**
251** When eOperator!=0, prereqRight and prereqAll record sets of cursor numbers,
252** but they do so indirectly. A single WhereMaskSet structure translates
253** cursor number into bits and the translated bit is stored in the prereq
254** fields. The translation is used in order to maximize the number of
255** bits that will fit in a Bitmask. The VDBE cursor numbers might be
256** spread out over the non-negative integers. For example, the cursor
257** numbers might be 3, 8, 9, 10, 20, 23, 41, and 45. The WhereMaskSet
258** translates these sparse cursor numbers into consecutive integers
259** beginning with 0 in order to make the best possible use of the available
260** bits in the Bitmask. So, in the example above, the cursor numbers
261** would be mapped into integers 0 through 7.
262**
263** The number of terms in a join is limited by the number of bits
264** in prereqRight and prereqAll. The default is 64 bits, hence SQLite
265** is only able to process joins with 64 or fewer tables.
266*/
267struct WhereTerm {
268 Expr *pExpr; /* Pointer to the subexpression that is this term */
269 WhereClause *pWC; /* The clause this term is part of */
270 LogEst truthProb; /* Probability of truth for this expression */
271 u16 wtFlags; /* TERM_xxx bit flags. See below */
272 u16 eOperator; /* A WO_xx value describing <op> */
273 u8 nChild; /* Number of children that must disable us */
274 u8 eMatchOp; /* Op for vtab MATCH/LIKE/GLOB/REGEXP terms */
275 int iParent; /* Disable pWC->a[iParent] when this term disabled */
276 int leftCursor; /* Cursor number of X in "X <op> <expr>" */
277 union {
278 struct {
279 int leftColumn; /* Column number of X in "X <op> <expr>" */
280 int iField; /* Field in (?,?,?) IN (SELECT...) vector */
281 } x; /* Opcode other than OP_OR or OP_AND */
282 WhereOrInfo *pOrInfo; /* Extra information if (eOperator & WO_OR)!=0 */
283 WhereAndInfo *pAndInfo; /* Extra information if (eOperator& WO_AND)!=0 */
284 } u;
285 Bitmask prereqRight; /* Bitmask of tables used by pExpr->pRight */
286 Bitmask prereqAll; /* Bitmask of tables referenced by pExpr */
287};
288
289/*
290** Allowed values of WhereTerm.wtFlags
291*/
292#define TERM_DYNAMIC 0x0001 /* Need to call sqlite3ExprDelete(db, pExpr) */
293#define TERM_VIRTUAL 0x0002 /* Added by the optimizer. Do not code */
294#define TERM_CODED 0x0004 /* This term is already coded */
295#define TERM_COPIED 0x0008 /* Has a child */
296#define TERM_ORINFO 0x0010 /* Need to free the WhereTerm.u.pOrInfo object */
297#define TERM_ANDINFO 0x0020 /* Need to free the WhereTerm.u.pAndInfo obj */
298#define TERM_OK 0x0040 /* Used during OR-clause processing */
299#define TERM_VNULL 0x0080 /* Manufactured x>NULL or x<=NULL term */
300#define TERM_LIKEOPT 0x0100 /* Virtual terms from the LIKE optimization */
301#define TERM_LIKECOND 0x0200 /* Conditionally this LIKE operator term */
302#define TERM_LIKE 0x0400 /* The original LIKE operator */
303#define TERM_IS 0x0800 /* Term.pExpr is an IS operator */
304#define TERM_VARSELECT 0x1000 /* Term.pExpr contains a correlated sub-query */
305#define TERM_HEURTRUTH 0x2000 /* Heuristic truthProb used */
306#ifdef SQLITE_ENABLE_STAT4
307# define TERM_HIGHTRUTH 0x4000 /* Term excludes few rows */
308#else
309# define TERM_HIGHTRUTH 0 /* Only used with STAT4 */
310#endif
311#define TERM_SLICE 0x8000 /* One slice of a row-value/vector comparison */
312
313/*
314** An instance of the WhereScan object is used as an iterator for locating
315** terms in the WHERE clause that are useful to the query planner.
316*/
317struct WhereScan {
318 WhereClause *pOrigWC; /* Original, innermost WhereClause */
319 WhereClause *pWC; /* WhereClause currently being scanned */
320 const char *zCollName; /* Required collating sequence, if not NULL */
321 Expr *pIdxExpr; /* Search for this index expression */
322 int k; /* Resume scanning at this->pWC->a[this->k] */
323 u32 opMask; /* Acceptable operators */
324 char idxaff; /* Must match this affinity, if zCollName!=NULL */
325 unsigned char iEquiv; /* Current slot in aiCur[] and aiColumn[] */
326 unsigned char nEquiv; /* Number of entries in aiCur[] and aiColumn[] */
327 int aiCur[11]; /* Cursors in the equivalence class */
328 i16 aiColumn[11]; /* Corresponding column number in the eq-class */
329};
330
331/*
332** An instance of the following structure holds all information about a
333** WHERE clause. Mostly this is a container for one or more WhereTerms.
334**
335** Explanation of pOuter: For a WHERE clause of the form
336**
337** a AND ((b AND c) OR (d AND e)) AND f
338**
339** There are separate WhereClause objects for the whole clause and for
340** the subclauses "(b AND c)" and "(d AND e)". The pOuter field of the
341** subclauses points to the WhereClause object for the whole clause.
342*/
343struct WhereClause {
344 WhereInfo *pWInfo; /* WHERE clause processing context */
345 WhereClause *pOuter; /* Outer conjunction */
346 u8 op; /* Split operator. TK_AND or TK_OR */
347 u8 hasOr; /* True if any a[].eOperator is WO_OR */
348 int nTerm; /* Number of terms */
349 int nSlot; /* Number of entries in a[] */
350 int nBase; /* Number of terms through the last non-Virtual */
351 WhereTerm *a; /* Each a[] describes a term of the WHERE cluase */
352#if defined(SQLITE_SMALL_STACK)
353 WhereTerm aStatic[1]; /* Initial static space for a[] */
354#else
355 WhereTerm aStatic[8]; /* Initial static space for a[] */
356#endif
357};
358
359/*
360** A WhereTerm with eOperator==WO_OR has its u.pOrInfo pointer set to
361** a dynamically allocated instance of the following structure.
362*/
363struct WhereOrInfo {
364 WhereClause wc; /* Decomposition into subterms */
365 Bitmask indexable; /* Bitmask of all indexable tables in the clause */
366};
367
368/*
369** A WhereTerm with eOperator==WO_AND has its u.pAndInfo pointer set to
370** a dynamically allocated instance of the following structure.
371*/
372struct WhereAndInfo {
373 WhereClause wc; /* The subexpression broken out */
374};
375
376/*
377** An instance of the following structure keeps track of a mapping
378** between VDBE cursor numbers and bits of the bitmasks in WhereTerm.
379**
380** The VDBE cursor numbers are small integers contained in
381** SrcItem.iCursor and Expr.iTable fields. For any given WHERE
382** clause, the cursor numbers might not begin with 0 and they might
383** contain gaps in the numbering sequence. But we want to make maximum
384** use of the bits in our bitmasks. This structure provides a mapping
385** from the sparse cursor numbers into consecutive integers beginning
386** with 0.
387**
388** If WhereMaskSet.ix[A]==B it means that The A-th bit of a Bitmask
389** corresponds VDBE cursor number B. The A-th bit of a bitmask is 1<<A.
390**
391** For example, if the WHERE clause expression used these VDBE
392** cursors: 4, 5, 8, 29, 57, 73. Then the WhereMaskSet structure
393** would map those cursor numbers into bits 0 through 5.
394**
395** Note that the mapping is not necessarily ordered. In the example
396** above, the mapping might go like this: 4->3, 5->1, 8->2, 29->0,
397** 57->5, 73->4. Or one of 719 other combinations might be used. It
398** does not really matter. What is important is that sparse cursor
399** numbers all get mapped into bit numbers that begin with 0 and contain
400** no gaps.
401*/
402struct WhereMaskSet {
403 int bVarSelect; /* Used by sqlite3WhereExprUsage() */
404 int n; /* Number of assigned cursor values */
405 int ix[BMS]; /* Cursor assigned to each bit */
406};
407
408/*
409** This object is a convenience wrapper holding all information needed
410** to construct WhereLoop objects for a particular query.
411*/
412struct WhereLoopBuilder {
413 WhereInfo *pWInfo; /* Information about this WHERE */
414 WhereClause *pWC; /* WHERE clause terms */
415 WhereLoop *pNew; /* Template WhereLoop */
416 WhereOrSet *pOrSet; /* Record best loops here, if not NULL */
417#ifdef SQLITE_ENABLE_STAT4
418 UnpackedRecord *pRec; /* Probe for stat4 (if required) */
419 int nRecValid; /* Number of valid fields currently in pRec */
420#endif
421 unsigned char bldFlags1; /* First set of SQLITE_BLDF_* flags */
422 unsigned char bldFlags2; /* Second set of SQLITE_BLDF_* flags */
423 unsigned int iPlanLimit; /* Search limiter */
424};
425
426/* Allowed values for WhereLoopBuider.bldFlags */
427#define SQLITE_BLDF1_INDEXED 0x0001 /* An index is used */
428#define SQLITE_BLDF1_UNIQUE 0x0002 /* All keys of a UNIQUE index used */
429
430#define SQLITE_BLDF2_2NDPASS 0x0004 /* Second builder pass needed */
431
432/* The WhereLoopBuilder.iPlanLimit is used to limit the number of
433** index+constraint combinations the query planner will consider for a
434** particular query. If this parameter is unlimited, then certain
435** pathological queries can spend excess time in the sqlite3WhereBegin()
436** routine. The limit is high enough that is should not impact real-world
437** queries.
438**
439** SQLITE_QUERY_PLANNER_LIMIT is the baseline limit. The limit is
440** increased by SQLITE_QUERY_PLANNER_LIMIT_INCR before each term of the FROM
441** clause is processed, so that every table in a join is guaranteed to be
442** able to propose a some index+constraint combinations even if the initial
443** baseline limit was exhausted by prior tables of the join.
444*/
445#ifndef SQLITE_QUERY_PLANNER_LIMIT
446# define SQLITE_QUERY_PLANNER_LIMIT 20000
447#endif
448#ifndef SQLITE_QUERY_PLANNER_LIMIT_INCR
449# define SQLITE_QUERY_PLANNER_LIMIT_INCR 1000
450#endif
451
452/*
453** The WHERE clause processing routine has two halves. The
454** first part does the start of the WHERE loop and the second
455** half does the tail of the WHERE loop. An instance of
456** this structure is returned by the first half and passed
457** into the second half to give some continuity.
458**
459** An instance of this object holds the complete state of the query
460** planner.
461*/
462struct WhereInfo {
463 Parse *pParse; /* Parsing and code generating context */
464 SrcList *pTabList; /* List of tables in the join */
465 ExprList *pOrderBy; /* The ORDER BY clause or NULL */
466 ExprList *pResultSet; /* Result set of the query */
467#if WHERETRACE_ENABLED
468 Expr *pWhere; /* The complete WHERE clause */
469#endif
470 Select *pSelect; /* The entire SELECT statement containing WHERE */
471 int aiCurOnePass[2]; /* OP_OpenWrite cursors for the ONEPASS opt */
472 int iContinue; /* Jump here to continue with next record */
473 int iBreak; /* Jump here to break out of the loop */
474 int savedNQueryLoop; /* pParse->nQueryLoop outside the WHERE loop */
475 u16 wctrlFlags; /* Flags originally passed to sqlite3WhereBegin() */
476 LogEst iLimit; /* LIMIT if wctrlFlags has WHERE_USE_LIMIT */
477 u8 nLevel; /* Number of nested loop */
478 i8 nOBSat; /* Number of ORDER BY terms satisfied by indices */
479 u8 eOnePass; /* ONEPASS_OFF, or _SINGLE, or _MULTI */
480 u8 eDistinct; /* One of the WHERE_DISTINCT_* values */
481 unsigned bDeferredSeek :1; /* Uses OP_DeferredSeek */
482 unsigned untestedTerms :1; /* Not all WHERE terms resolved by outer loop */
483 unsigned bOrderedInnerLoop:1;/* True if only the inner-most loop is ordered */
484 unsigned sorted :1; /* True if really sorted (not just grouped) */
485 LogEst nRowOut; /* Estimated number of output rows */
486 int iTop; /* The very beginning of the WHERE loop */
487 int iEndWhere; /* End of the WHERE clause itself */
488 WhereLoop *pLoops; /* List of all WhereLoop objects */
489 WhereMemBlock *pMemToFree;/* Memory to free when this object destroyed */
490 Bitmask revMask; /* Mask of ORDER BY terms that need reversing */
491 WhereClause sWC; /* Decomposition of the WHERE clause */
492 WhereMaskSet sMaskSet; /* Map cursor numbers to bitmasks */
493 WhereLevel a[1]; /* Information about each nest loop in WHERE */
494};
495
496/*
497** Private interfaces - callable only by other where.c routines.
498**
499** where.c:
500*/
501Bitmask sqlite3WhereGetMask(WhereMaskSet*,int);
502#ifdef WHERETRACE_ENABLED
503void sqlite3WhereClausePrint(WhereClause *pWC);
504void sqlite3WhereTermPrint(WhereTerm *pTerm, int iTerm);
505void sqlite3WhereLoopPrint(WhereLoop *p, WhereClause *pWC);
506#endif
507WhereTerm *sqlite3WhereFindTerm(
508 WhereClause *pWC, /* The WHERE clause to be searched */
509 int iCur, /* Cursor number of LHS */
510 int iColumn, /* Column number of LHS */
511 Bitmask notReady, /* RHS must not overlap with this mask */
512 u32 op, /* Mask of WO_xx values describing operator */
513 Index *pIdx /* Must be compatible with this index, if not NULL */
514);
515void *sqlite3WhereMalloc(WhereInfo *pWInfo, u64 nByte);
516void *sqlite3WhereRealloc(WhereInfo *pWInfo, void *pOld, u64 nByte);
517
518/* wherecode.c: */
519#ifndef SQLITE_OMIT_EXPLAIN
520int sqlite3WhereExplainOneScan(
521 Parse *pParse, /* Parse context */
522 SrcList *pTabList, /* Table list this loop refers to */
523 WhereLevel *pLevel, /* Scan to write OP_Explain opcode for */
524 u16 wctrlFlags /* Flags passed to sqlite3WhereBegin() */
525);
526int sqlite3WhereExplainBloomFilter(
527 const Parse *pParse, /* Parse context */
528 const WhereInfo *pWInfo, /* WHERE clause */
529 const WhereLevel *pLevel /* Bloom filter on this level */
530);
531#else
532# define sqlite3WhereExplainOneScan(u,v,w,x) 0
533# define sqlite3WhereExplainBloomFilter(u,v,w) 0
534#endif /* SQLITE_OMIT_EXPLAIN */
535#ifdef SQLITE_ENABLE_STMT_SCANSTATUS
536void sqlite3WhereAddScanStatus(
537 Vdbe *v, /* Vdbe to add scanstatus entry to */
538 SrcList *pSrclist, /* FROM clause pLvl reads data from */
539 WhereLevel *pLvl, /* Level to add scanstatus() entry for */
540 int addrExplain /* Address of OP_Explain (or 0) */
541);
542#else
543# define sqlite3WhereAddScanStatus(a, b, c, d) ((void)d)
544#endif
545Bitmask sqlite3WhereCodeOneLoopStart(
546 Parse *pParse, /* Parsing context */
547 Vdbe *v, /* Prepared statement under construction */
548 WhereInfo *pWInfo, /* Complete information about the WHERE clause */
549 int iLevel, /* Which level of pWInfo->a[] should be coded */
550 WhereLevel *pLevel, /* The current level pointer */
551 Bitmask notReady /* Which tables are currently available */
552);
553SQLITE_NOINLINE void sqlite3WhereRightJoinLoop(
554 WhereInfo *pWInfo,
555 int iLevel,
556 WhereLevel *pLevel
557);
558
559/* whereexpr.c: */
560void sqlite3WhereClauseInit(WhereClause*,WhereInfo*);
561void sqlite3WhereClauseClear(WhereClause*);
562void sqlite3WhereSplit(WhereClause*,Expr*,u8);
563void sqlite3WhereAddLimit(WhereClause*, Select*);
564Bitmask sqlite3WhereExprUsage(WhereMaskSet*, Expr*);
565Bitmask sqlite3WhereExprUsageNN(WhereMaskSet*, Expr*);
566Bitmask sqlite3WhereExprListUsage(WhereMaskSet*, ExprList*);
567void sqlite3WhereExprAnalyze(SrcList*, WhereClause*);
568void sqlite3WhereTabFuncArgs(Parse*, SrcItem*, WhereClause*);
569
570
571
572
573
574/*
575** Bitmasks for the operators on WhereTerm objects. These are all
576** operators that are of interest to the query planner. An
577** OR-ed combination of these values can be used when searching for
578** particular WhereTerms within a WhereClause.
579**
580** Value constraints:
581** WO_EQ == SQLITE_INDEX_CONSTRAINT_EQ
582** WO_LT == SQLITE_INDEX_CONSTRAINT_LT
583** WO_LE == SQLITE_INDEX_CONSTRAINT_LE
584** WO_GT == SQLITE_INDEX_CONSTRAINT_GT
585** WO_GE == SQLITE_INDEX_CONSTRAINT_GE
586*/
587#define WO_IN 0x0001
588#define WO_EQ 0x0002
589#define WO_LT (WO_EQ<<(TK_LT-TK_EQ))
590#define WO_LE (WO_EQ<<(TK_LE-TK_EQ))
591#define WO_GT (WO_EQ<<(TK_GT-TK_EQ))
592#define WO_GE (WO_EQ<<(TK_GE-TK_EQ))
593#define WO_AUX 0x0040 /* Op useful to virtual tables only */
594#define WO_IS 0x0080
595#define WO_ISNULL 0x0100
596#define WO_OR 0x0200 /* Two or more OR-connected terms */
597#define WO_AND 0x0400 /* Two or more AND-connected terms */
598#define WO_EQUIV 0x0800 /* Of the form A==B, both columns */
599#define WO_NOOP 0x1000 /* This term does not restrict search space */
600#define WO_ROWVAL 0x2000 /* A row-value term */
601
602#define WO_ALL 0x3fff /* Mask of all possible WO_* values */
603#define WO_SINGLE 0x01ff /* Mask of all non-compound WO_* values */
604
605/*
606** These are definitions of bits in the WhereLoop.wsFlags field.
607** The particular combination of bits in each WhereLoop help to
608** determine the algorithm that WhereLoop represents.
609*/
610#define WHERE_COLUMN_EQ 0x00000001 /* x=EXPR */
611#define WHERE_COLUMN_RANGE 0x00000002 /* x<EXPR and/or x>EXPR */
612#define WHERE_COLUMN_IN 0x00000004 /* x IN (...) */
613#define WHERE_COLUMN_NULL 0x00000008 /* x IS NULL */
614#define WHERE_CONSTRAINT 0x0000000f /* Any of the WHERE_COLUMN_xxx values */
615#define WHERE_TOP_LIMIT 0x00000010 /* x<EXPR or x<=EXPR constraint */
616#define WHERE_BTM_LIMIT 0x00000020 /* x>EXPR or x>=EXPR constraint */
617#define WHERE_BOTH_LIMIT 0x00000030 /* Both x>EXPR and x<EXPR */
618#define WHERE_IDX_ONLY 0x00000040 /* Use index only - omit table */
619#define WHERE_IPK 0x00000100 /* x is the INTEGER PRIMARY KEY */
620#define WHERE_INDEXED 0x00000200 /* WhereLoop.u.btree.pIndex is valid */
621#define WHERE_VIRTUALTABLE 0x00000400 /* WhereLoop.u.vtab is valid */
622#define WHERE_IN_ABLE 0x00000800 /* Able to support an IN operator */
623#define WHERE_ONEROW 0x00001000 /* Selects no more than one row */
624#define WHERE_MULTI_OR 0x00002000 /* OR using multiple indices */
625#define WHERE_AUTO_INDEX 0x00004000 /* Uses an ephemeral index */
626#define WHERE_SKIPSCAN 0x00008000 /* Uses the skip-scan algorithm */
627#define WHERE_UNQ_WANTED 0x00010000 /* WHERE_ONEROW would have been helpful*/
628#define WHERE_PARTIALIDX 0x00020000 /* The automatic index is partial */
629#define WHERE_IN_EARLYOUT 0x00040000 /* Perhaps quit IN loops early */
630#define WHERE_BIGNULL_SORT 0x00080000 /* Column nEq of index is BIGNULL */
631#define WHERE_IN_SEEKSCAN 0x00100000 /* Seek-scan optimization for IN */
632#define WHERE_TRANSCONS 0x00200000 /* Uses a transitive constraint */
633#define WHERE_BLOOMFILTER 0x00400000 /* Consider using a Bloom-filter */
634#define WHERE_SELFCULL 0x00800000 /* nOut reduced by extra WHERE terms */
635#define WHERE_OMIT_OFFSET 0x01000000 /* Set offset counter to zero */
636#define WHERE_VIEWSCAN 0x02000000 /* A full-scan of a VIEW or subquery */
637
638#endif /* !defined(SQLITE_WHEREINT_H) */
639