functions/Find-DbaDbDuplicateIndex.ps1

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
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
function Find-DbaDbDuplicateIndex {
    <#
    .SYNOPSIS
        Find duplicate and overlapping indexes.
 
    .DESCRIPTION
        This command will help you to find duplicate and overlapping indexes on a database or a list of databases.
 
        On SQL Server 2008 and higher, the IsFiltered property will also be checked
 
        Only supports CLUSTERED and NONCLUSTERED indexes.
 
        Output:
        TableName
        IndexName
        KeyColumns
        IncludedColumns
        IndexSizeMB
        IndexType
        CompressionDescription (When 2008+)
        [RowCount]
        IsDisabled
        IsFiltered (When 2008+)
 
    .PARAMETER SqlInstance
        The target SQL Server instance or instances.
 
    .PARAMETER SqlCredential
        Login to the target instance using alternative credentials. Windows and SQL Authentication supported. Accepts credential objects (Get-Credential)
 
    .PARAMETER Database
        The database(s) to process. Options for this list are auto-populated from the server. If unspecified, all databases will be processed.
 
    .PARAMETER IncludeOverlapping
        If this switch is enabled, indexes which are partially duplicated will be returned.
 
        Example: If the first key column is the same between two indexes, but one has included columns and the other not, this will be shown.
 
    .PARAMETER EnableException
        By default, when something goes wrong we try to catch it, interpret it and give you a friendly warning message.
        This avoids overwhelming you with "sea of red" exceptions, but is inconvenient because it basically disables advanced scripting.
        Using this switch turns this "nice by default" feature off and enables you to catch exceptions with your own try/catch.
 
    .NOTES
        Tags: Index
        Author: Claudio Silva (@ClaudioESSilva)
 
        Website: https://dbatools.io
        Copyright: (c) 2018 by dbatools, licensed under MIT
        License: MIT https://opensource.org/licenses/MIT
 
    .LINK
        https://dbatools.io/Find-DbaDbDuplicateIndex
 
    .EXAMPLE
        PS C:\> Find-DbaDbDuplicateIndex -SqlInstance sql2005
 
        Returns duplicate indexes found on sql2005
 
    .EXAMPLE
        PS C:\> Find-DbaDbDuplicateIndex -SqlInstance sql2017 -SqlCredential sqladmin
 
        Finds exact duplicate indexes on all user databases present on sql2017, using SQL authentication.
 
    .EXAMPLE
        PS C:\> Find-DbaDbDuplicateIndex -SqlInstance sql2017 -Database db1, db2
 
        Finds exact duplicate indexes on the db1 and db2 databases.
 
    .EXAMPLE
        PS C:\> Find-DbaDbDuplicateIndex -SqlInstance sql2017 -IncludeOverlapping
 
        Finds both duplicate and overlapping indexes on all user databases.
 
    #>

    [CmdletBinding()]
    param (
        [parameter(Mandatory, ValueFromPipeline)]
        [DbaInstanceParameter[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [object[]]$Database,
        [switch]$IncludeOverlapping,
        [switch]$EnableException
    )

    begin {
        $exactDuplicateQuery2005 = "
            WITH CTE_IndexCols
            AS (
                SELECT i.[object_id]
                    ,i.index_id
                    ,OBJECT_SCHEMA_NAME(i.[object_id]) AS SchemaName
                    ,OBJECT_NAME(i.[object_id]) AS TableName
                    ,NAME AS IndexName
                    ,ISNULL(STUFF((
                                SELECT ', ' + col.NAME + ' ' + CASE
                                        WHEN idxCol.is_descending_key = 1
                                            THEN 'DESC'
                                        ELSE 'ASC'
                                        END -- Include column order (ASC / DESC)
                                FROM sys.index_columns idxCol
                                INNER JOIN sys.columns col ON idxCol.[object_id] = col.[object_id]
                                    AND idxCol.column_id = col.column_id
                                WHERE i.[object_id] = idxCol.[object_id]
                                    AND i.index_id = idxCol.index_id
                                    AND idxCol.is_included_column = 0
                                ORDER BY idxCol.key_ordinal
                                FOR XML PATH('')
                                ), 1, 2, ''), '') AS KeyColumns
                    ,ISNULL(STUFF((
                                SELECT ', ' + col.NAME + ' ' + CASE
                                        WHEN idxCol.is_descending_key = 1
                                            THEN 'DESC'
                                        ELSE 'ASC'
                                        END -- Include column order (ASC / DESC)
                                FROM sys.index_columns idxCol
                                INNER JOIN sys.columns col ON idxCol.[object_id] = col.[object_id]
                                    AND idxCol.column_id = col.column_id
                                WHERE i.[object_id] = idxCol.[object_id]
                                    AND i.index_id = idxCol.index_id
                                    AND idxCol.is_included_column = 1
                                ORDER BY idxCol.key_ordinal
                                FOR XML PATH('')
                                ), 1, 2, ''), '') AS IncludedColumns
                    ,i.[type_desc] AS IndexType
                    ,i.is_disabled AS IsDisabled
                FROM sys.indexes AS i
                WHERE i.index_id > 0 -- Exclude HEAPS
                    AND i.[type_desc] IN (
                        'CLUSTERED'
                        ,'NONCLUSTERED'
                        )
                    AND OBJECT_SCHEMA_NAME(i.[object_id]) <> 'sys'
                )
                ,CTE_IndexSpace
            AS (
                SELECT s.[object_id]
                    ,s.index_id
                    ,SUM(s.[used_page_count]) * 8 / 1024.0 AS IndexSizeMB
                    ,SUM(p.[rows]) AS [RowCount]
                FROM sys.dm_db_partition_stats AS s
                INNER JOIN sys.partitions p WITH (NOLOCK) ON s.[partition_id] = p.[partition_id]
                    AND s.[object_id] = p.[object_id]
                    AND s.index_id = p.index_id
                WHERE s.index_id > 0 -- Exclude HEAPS
                    AND OBJECT_SCHEMA_NAME(s.[object_id]) <> 'sys'
                GROUP BY s.[object_id]
                    ,s.index_id
                )
            SELECT DB_NAME() AS DatabaseName
                ,CI1.SchemaName + '.' + CI1.TableName AS 'TableName'
                ,CI1.IndexName
                ,CI1.KeyColumns
                ,CI1.IncludedColumns
                ,CI1.IndexType
                ,COALESCE(CSPC.IndexSizeMB,0) AS 'IndexSizeMB'
                ,COALESCE(CSPC.[RowCount],0) AS 'RowCount'
                ,CI1.IsDisabled
            FROM CTE_IndexCols AS CI1
            LEFT JOIN CTE_IndexSpace AS CSPC ON CI1.[object_id] = CSPC.[object_id]
                AND CI1.index_id = CSPC.index_id
            WHERE EXISTS (
                    SELECT 1
                    FROM CTE_IndexCols CI2
                    WHERE CI1.SchemaName = CI2.SchemaName
                        AND CI1.TableName = CI2.TableName
                        AND CI1.KeyColumns = CI2.KeyColumns
                        AND CI1.IncludedColumns = CI2.IncludedColumns
                        AND CI1.IndexName <> CI2.IndexName
                    )"


        $overlappingQuery2005 = "
            WITH CTE_IndexCols
            AS (
                SELECT i.[object_id]
                    ,i.index_id
                    ,OBJECT_SCHEMA_NAME(i.[object_id]) AS SchemaName
                    ,OBJECT_NAME(i.[object_id]) AS TableName
                    ,NAME AS IndexName
                    ,ISNULL(STUFF((
                                SELECT ', ' + col.NAME + ' ' + CASE
                                        WHEN idxCol.is_descending_key = 1
                                            THEN 'DESC'
                                        ELSE 'ASC'
                                        END -- Include column order (ASC / DESC)
                                FROM sys.index_columns idxCol
                                INNER JOIN sys.columns col ON idxCol.[object_id] = col.[object_id]
                                    AND idxCol.column_id = col.column_id
                                WHERE i.[object_id] = idxCol.[object_id]
                                    AND i.index_id = idxCol.index_id
                                    AND idxCol.is_included_column = 0
                                ORDER BY idxCol.key_ordinal
                                FOR XML PATH('')
                                ), 1, 2, ''), '') AS KeyColumns
                    ,ISNULL(STUFF((
                                SELECT ', ' + col.NAME + ' ' + CASE
                                        WHEN idxCol.is_descending_key = 1
                                            THEN 'DESC'
                                        ELSE 'ASC'
                                        END -- Include column order (ASC / DESC)
                                FROM sys.index_columns idxCol
                                INNER JOIN sys.columns col ON idxCol.[object_id] = col.[object_id]
                                    AND idxCol.column_id = col.column_id
                                WHERE i.[object_id] = idxCol.[object_id]
                                    AND i.index_id = idxCol.index_id
                                    AND idxCol.is_included_column = 1
                                ORDER BY idxCol.key_ordinal
                                FOR XML PATH('')
                                ), 1, 2, ''), '') AS IncludedColumns
                    ,i.[type_desc] AS IndexType
                    ,i.is_disabled AS IsDisabled
                FROM sys.indexes AS i
                WHERE i.index_id > 0 -- Exclude HEAPS
                    AND i.[type_desc] IN (
                        'CLUSTERED'
                        ,'NONCLUSTERED'
                        )
                    AND OBJECT_SCHEMA_NAME(i.[object_id]) <> 'sys'
                )
                ,CTE_IndexSpace
            AS (
                SELECT s.[object_id]
                    ,s.index_id
                    ,SUM(s.[used_page_count]) * 8 / 1024.0 AS IndexSizeMB
                    ,SUM(p.[rows]) AS [RowCount]
                FROM sys.dm_db_partition_stats AS s
                INNER JOIN sys.partitions p WITH (NOLOCK) ON s.[partition_id] = p.[partition_id]
                    AND s.[object_id] = p.[object_id]
                    AND s.index_id = p.index_id
                WHERE s.index_id > 0 -- Exclude HEAPS
                    AND OBJECT_SCHEMA_NAME(s.[object_id]) <> 'sys'
                GROUP BY s.[object_id]
                    ,s.index_id
                )
            SELECT DB_NAME() AS DatabaseName
                ,CI1.SchemaName + '.' + CI1.TableName AS 'TableName'
                ,CI1.IndexName
                ,CI1.KeyColumns
                ,CI1.IncludedColumns
                ,CI1.IndexType
                ,COALESCE(CSPC.IndexSizeMB,0) AS 'IndexSizeMB'
                ,COALESCE(CSPC.[RowCount],0) AS 'RowCount'
                ,CI1.IsDisabled
            FROM CTE_IndexCols AS CI1
            LEFT JOIN CTE_IndexSpace AS CSPC ON CI1.[object_id] = CSPC.[object_id]
                AND CI1.index_id = CSPC.index_id
            WHERE EXISTS (
                    SELECT 1
                    FROM CTE_IndexCols CI2
                    WHERE CI1.SchemaName = CI2.SchemaName
                        AND CI1.TableName = CI2.TableName
                        AND (
                            (
                                CI1.KeyColumns LIKE CI2.KeyColumns + '%'
                                AND SUBSTRING(CI1.KeyColumns, LEN(CI2.KeyColumns) + 1, 1) = ' '
                                )
                            OR (
                                CI2.KeyColumns LIKE CI1.KeyColumns + '%'
                                AND SUBSTRING(CI2.KeyColumns, LEN(CI1.KeyColumns) + 1, 1) = ' '
                                )
                            )
                        AND CI1.IndexName <> CI2.IndexName
                    )"


        # Support Compression 2008+
        $exactDuplicateQuery = "
            WITH CTE_IndexCols
            AS (
                SELECT i.[object_id]
                    ,i.index_id
                    ,OBJECT_SCHEMA_NAME(i.[object_id]) AS SchemaName
                    ,OBJECT_NAME(i.[object_id]) AS TableName
                    ,NAME AS IndexName
                    ,ISNULL(STUFF((
                                SELECT ', ' + col.NAME + ' ' + CASE
                                        WHEN idxCol.is_descending_key = 1
                                            THEN 'DESC'
                                        ELSE 'ASC'
                                        END -- Include column order (ASC / DESC)
                                FROM sys.index_columns idxCol
                                INNER JOIN sys.columns col ON idxCol.[object_id] = col.[object_id]
                                    AND idxCol.column_id = col.column_id
                                WHERE i.[object_id] = idxCol.[object_id]
                                    AND i.index_id = idxCol.index_id
                                    AND idxCol.is_included_column = 0
                                ORDER BY idxCol.key_ordinal
                                FOR XML PATH('')
                                ), 1, 2, ''), '') AS KeyColumns
                    ,ISNULL(STUFF((
                                SELECT ', ' + col.NAME + ' ' + CASE
                                        WHEN idxCol.is_descending_key = 1
                                            THEN 'DESC'
                                        ELSE 'ASC'
                                        END -- Include column order (ASC / DESC)
                                FROM sys.index_columns idxCol
                                INNER JOIN sys.columns col ON idxCol.[object_id] = col.[object_id]
                                    AND idxCol.column_id = col.column_id
                                WHERE i.[object_id] = idxCol.[object_id]
                                    AND i.index_id = idxCol.index_id
                                    AND idxCol.is_included_column = 1
                                ORDER BY idxCol.key_ordinal
                                FOR XML PATH('')
                                ), 1, 2, ''), '') AS IncludedColumns
                    ,i.[type_desc] AS IndexType
                    ,i.is_disabled AS IsDisabled
                    ,i.has_filter AS IsFiltered
                FROM sys.indexes AS i
                WHERE i.index_id > 0 -- Exclude HEAPS
                    AND i.[type_desc] IN (
                        'CLUSTERED'
                        ,'NONCLUSTERED'
                        )
                    AND OBJECT_SCHEMA_NAME(i.[object_id]) <> 'sys'
                )
                ,CTE_IndexSpace
            AS (
                SELECT s.[object_id]
                    ,s.index_id
                    ,SUM(s.[used_page_count]) * 8 / 1024.0 AS IndexSizeMB
                    ,SUM(p.[rows]) AS [RowCount]
                    ,p.data_compression_desc AS CompressionDescription
                FROM sys.dm_db_partition_stats AS s
                INNER JOIN sys.partitions p WITH (NOLOCK) ON s.[partition_id] = p.[partition_id]
                    AND s.[object_id] = p.[object_id]
                    AND s.index_id = p.index_id
                WHERE s.index_id > 0 -- Exclude HEAPS
                    AND OBJECT_SCHEMA_NAME(s.[object_id]) <> 'sys'
                GROUP BY s.[object_id]
                    ,s.index_id
                    ,p.data_compression_desc
                )
            SELECT DB_NAME() AS DatabaseName
                ,CI1.SchemaName + '.' + CI1.TableName AS 'TableName'
                ,CI1.IndexName
                ,CI1.KeyColumns
                ,CI1.IncludedColumns
                ,CI1.IndexType
                ,COALESCE(CSPC.IndexSizeMB,0) AS 'IndexSizeMB'
                ,COALESCE(CSPC.CompressionDescription, 'NONE') AS 'CompressionDescription'
                ,COALESCE(CSPC.[RowCount],0) AS 'RowCount'
                ,CI1.IsDisabled
                ,CI1.IsFiltered
            FROM CTE_IndexCols AS CI1
            LEFT JOIN CTE_IndexSpace AS CSPC ON CI1.[object_id] = CSPC.[object_id]
                AND CI1.index_id = CSPC.index_id
            WHERE EXISTS (
                    SELECT 1
                    FROM CTE_IndexCols CI2
                    WHERE CI1.SchemaName = CI2.SchemaName
                        AND CI1.TableName = CI2.TableName
                        AND CI1.KeyColumns = CI2.KeyColumns
                        AND CI1.IncludedColumns = CI2.IncludedColumns
                        AND CI1.IsFiltered = CI2.IsFiltered
                        AND CI1.IndexName <> CI2.IndexName
                    )"


        $overlappingQuery = "
            WITH CTE_IndexCols AS
            (
                SELECT
                        i.[object_id]
                        ,i.index_id
                        ,OBJECT_SCHEMA_NAME(i.[object_id]) AS SchemaName
                        ,OBJECT_NAME(i.[object_id]) AS TableName
                        ,Name AS IndexName
                        ,ISNULL(STUFF((SELECT ', ' + col.NAME + ' ' + CASE
                                                                    WHEN idxCol.is_descending_key = 1 THEN 'DESC'
                                                                    ELSE 'ASC'
                                                                END -- Include column order (ASC / DESC)
                                FROM sys.index_columns idxCol
                                    INNER JOIN sys.columns col
                                    ON idxCol.[object_id] = col.[object_id]
                                    AND idxCol.column_id = col.column_id
                                WHERE i.[object_id] = idxCol.[object_id]
                                AND i.index_id = idxCol.index_id
                                AND idxCol.is_included_column = 0
                                ORDER BY idxCol.key_ordinal
                        FOR XML PATH('')), 1, 2, ''), '') AS KeyColumns
                        ,ISNULL(STUFF((SELECT ', ' + col.NAME + ' ' + CASE
                                                                    WHEN idxCol.is_descending_key = 1 THEN 'DESC'
                                                                    ELSE 'ASC'
                                                                END -- Include column order (ASC / DESC)
                                FROM sys.index_columns idxCol
                                    INNER JOIN sys.columns col
                                    ON idxCol.[object_id] = col.[object_id]
                                    AND idxCol.column_id = col.column_id
                                WHERE i.[object_id] = idxCol.[object_id]
                                AND i.index_id = idxCol.index_id
                                AND idxCol.is_included_column = 1
                                ORDER BY idxCol.key_ordinal
                        FOR XML PATH('')), 1, 2, ''), '') AS IncludedColumns
                        ,i.[type_desc] AS IndexType
                        ,i.is_disabled AS IsDisabled
                        ,i.has_filter AS IsFiltered
                FROM sys.indexes AS i
                WHERE i.index_id > 0 -- Exclude HEAPS
                AND i.[type_desc] IN ('CLUSTERED', 'NONCLUSTERED')
                AND OBJECT_SCHEMA_NAME(i.[object_id]) <> 'sys'
            ),
            CTE_IndexSpace AS
            (
            SELECT
                        s.[object_id]
                        ,s.index_id
                        ,SUM(s.[used_page_count]) * 8 / 1024.0 AS IndexSizeMB
                        ,SUM(p.[rows]) AS [RowCount]
                        ,p.data_compression_desc AS CompressionDescription
                FROM sys.dm_db_partition_stats AS s
                    INNER JOIN sys.partitions p WITH (NOLOCK)
                    ON s.[partition_id] = p.[partition_id]
                    AND s.[object_id] = p.[object_id]
                    AND s.index_id = p.index_id
                WHERE s.index_id > 0 -- Exclude HEAPS
                    AND OBJECT_SCHEMA_NAME(s.[object_id]) <> 'sys'
                GROUP BY s.[object_id], s.index_id, p.data_compression_desc
            )
            SELECT
                    DB_NAME() AS DatabaseName
                    ,CI1.SchemaName + '.' + CI1.TableName AS 'TableName'
                    ,CI1.IndexName
                    ,CI1.KeyColumns
                    ,CI1.IncludedColumns
                    ,CI1.IndexType
                    ,COALESCE(CSPC.IndexSizeMB,0) AS 'IndexSizeMB'
                    ,COALESCE(CSPC.CompressionDescription, 'NONE') AS 'CompressionDescription'
                    ,COALESCE(CSPC.[RowCount],0) AS 'RowCount'
                    ,CI1.IsDisabled
                    ,CI1.IsFiltered
            FROM CTE_IndexCols AS CI1
                LEFT JOIN CTE_IndexSpace AS CSPC
                ON CI1.[object_id] = CSPC.[object_id]
                AND CI1.index_id = CSPC.index_id
            WHERE EXISTS (SELECT 1
                            FROM CTE_IndexCols CI2
                        WHERE CI1.SchemaName = CI2.SchemaName
                            AND CI1.TableName = CI2.TableName
                            AND (
                                        (CI1.KeyColumns like CI2.KeyColumns + '%' and SUBSTRING(CI1.KeyColumns,LEN(CI2.KeyColumns)+1,1) = ' ')
                                    OR (CI2.KeyColumns like CI1.KeyColumns + '%' and SUBSTRING(CI2.KeyColumns,LEN(CI1.KeyColumns)+1,1) = ' ')
                                )
                            AND CI1.IsFiltered = CI2.IsFiltered
                            AND CI1.IndexName <> CI2.IndexName
                        )"

    }
    process {
        if (Test-FunctionInterrupt) { return }

        foreach ($instance in $sqlinstance) {
            try {
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $sqlcredential -MinimumVersion 9
            } catch {
                Stop-Function -Message "Error occurred while establishing connection to $instance" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
            }

            if ($database) {
                $databases = $server.Databases | Where-Object Name -in $database
            } else {
                $databases = $server.Databases | Where-Object IsAccessible -eq $true
            }

            foreach ($db in $databases) {
                try {
                    Write-Message -Level Verbose -Message "Getting indexes from database '$db'."

                    $query = if ($server.versionMajor -eq 9) {
                        if ($IncludeOverlapping) { $overlappingQuery2005 }
                        else { $exactDuplicateQuery2005 }
                    } else {
                        if ($IncludeOverlapping) { $overlappingQuery }
                        else { $exactDuplicateQuery }
                    }

                    $db.Query($query)

                } catch {
                    Stop-Function -Message "Query failure" -Target $db
                }
            }
        }
    }
}