1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
/* Copyright (C) 2003 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#ifndef NdbIndexScanOperation_H
#define NdbIndexScanOperation_H
#include <NdbScanOperation.hpp>
/**
* @class NdbIndexScanOperation
* @brief Class of scan operations for use to scan ordered index
*/
class NdbIndexScanOperation : public NdbScanOperation {
#ifndef DOXYGEN_SHOULD_SKIP_INTERNAL
friend class Ndb;
friend class NdbTransaction;
friend class NdbResultSet;
friend class NdbOperation;
friend class NdbScanOperation;
#endif
public:
/**
* readTuples using ordered index
*
* @param lock_mode Lock mode
* @param batch No of rows to fetch from each fragment at a time
* @param parallel No of fragments to scan in parallel
* @param order_by Order result set in index order
* @param order_desc Order descending, ignored unless order_by
* @param read_range_no Enable reading of range no using @ref get_range_no
* @returns 0 for success and -1 for failure
* @see NdbScanOperation::readTuples
*/
int readTuples(LockMode lock_mode = LM_Read,
Uint32 batch = 0,
Uint32 parallel = 0,
bool order_by = false,
bool order_desc = false,
bool read_range_no = false);
/**
* Type of ordered index key bound. The values (0-4) will not change
* and can be used explicitly (e.g. they could be computed).
*/
enum BoundType {
BoundLE = 0, ///< lower bound
BoundLT = 1, ///< lower bound, strict
BoundGE = 2, ///< upper bound
BoundGT = 3, ///< upper bound, strict
BoundEQ = 4 ///< equality
};
/**
* Define bound on index key in range scan.
*
* Each index key can have lower and/or upper bound. Setting the key
* equal to a value defines both upper and lower bounds. The bounds
* can be defined in any order. Conflicting definitions is an error.
*
* For equality, it is better to use BoundEQ instead of the equivalent
* pair of BoundLE and BoundGE. This is especially true when table
* partition key is an initial part of the index key.
*
* The sets of lower and upper bounds must be on initial sequences of
* index keys. All but possibly the last bound must be non-strict.
* So "a >= 2 and b > 3" is ok but "a > 2 and b >= 3" is not.
*
* The scan may currently return tuples for which the bounds are not
* satisfied. For example, "a <= 2 and b <= 3" scans the index up to
* (a=2, b=3) but also returns any (a=1, b=4).
*
* NULL is treated like a normal value which is less than any not-NULL
* value and equal to another NULL value. To compare against NULL use
* setBound with null pointer (0).
*
* An index stores also all-NULL keys. Doing index scan with empty
* bound set returns all table tuples.
*
* @param attr Attribute name, alternatively:
* @param type Type of bound
* @param value Pointer to bound value, 0 for NULL
* @param len Value length in bytes.
* Fixed per datatype and can be omitted
* @return 0 if successful otherwise -1
*/
int setBound(const char* attr, int type, const void* value, Uint32 len = 0);
/**
* Define bound on index key in range scan using index column id.
* See the other setBound() method for details.
*/
int setBound(Uint32 anAttrId, int type, const void* aValue, Uint32 len = 0);
/**
* Reset bounds and put operation in list that will be
* sent on next execute
*/
int reset_bounds(bool forceSend = false);
/**
* Marks end of a bound,
* used when batching index reads (multiple ranges)
*/
int end_of_bound(Uint32 range_no);
/**
* Return range no for current row
*/
int get_range_no();
/**
* Is current scan sorted
*/
bool getSorted() const { return m_ordered; }
/**
* Is current scan sorted descending
*/
bool getDescending() const { return m_descending; }
private:
NdbIndexScanOperation(Ndb* aNdb);
virtual ~NdbIndexScanOperation();
int setBound(const NdbColumnImpl*, int type, const void* aValue, Uint32 len);
int insertBOUNDS(Uint32 * data, Uint32 sz);
virtual int equal_impl(const NdbColumnImpl*, const char*, Uint32);
virtual NdbRecAttr* getValue_impl(const NdbColumnImpl*, char*);
void fix_get_values();
int next_result_ordered(bool fetchAllowed, bool forceSend = false);
int send_next_scan_ordered(Uint32 idx, bool forceSend = false);
int compare(Uint32 key, Uint32 cols, const NdbReceiver*, const NdbReceiver*);
Uint32 m_sort_columns;
Uint32 m_this_bound_start;
Uint32 * m_first_bound_word;
};
#endif
|
