functions/Test-DbaIdentityUsage.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
function Test-DbaIdentityUsage {
    <#
        .SYNOPSIS
            Displays information relating to IDENTITY seed usage. Works on SQL Server 2008 and above.
 
        .DESCRIPTION
            IDENTITY seeds have max values based off of their data type. This module will locate identity columns and report the seed usage.
 
        .PARAMETER SqlInstance
            Allows you to specify a comma separated list of servers to query.
 
        .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 - this list is auto-populated from the server. If unspecified, all databases will be processed.
 
        .PARAMETER ExcludeDatabase
            The database(s) to exclude - this list is auto-populated from the server
 
        .PARAMETER Threshold
            Allows you to specify a minimum % of the seed range being utilized. This can be used to ignore seeds that have only utilized a small fraction of the range.
 
        .PARAMETER ExcludeSystemDb
            Allows you to suppress output on system databases
 
        .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
            Author: Brandon Abshire, netnerds.net
            Tags: Identity, Table, Column
 
            Website: https://dbatools.io
            Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
            License: MIT https://opensource.org/licenses/MIT
 
        .LINK
            https://dbatools.io/Test-DbaIdentityUsage
 
        .EXAMPLE
            Test-DbaIdentityUsage -SqlInstance sql2008, sqlserver2012
 
            Check identity seeds for servers sql2008 and sqlserver2012.
 
        .EXAMPLE
            Test-DbaIdentityUsage -SqlInstance sql2008 -Database TestDB
 
            Check identity seeds on server sql2008 for only the TestDB database
 
        .EXAMPLE
            Test-DbaIdentityUsage -SqlInstance sql2008 -Database TestDB -Threshold 20
 
            Check identity seeds on server sql2008 for only the TestDB database, limiting results to 20% utilization of seed range or higher
    #>

    [CmdletBinding()]
    param (
        [parameter(Position = 0, Mandatory = $true, ValueFromPipeline = $True)]
        [Alias("ServerInstance", "SqlServer", "SqlServers")]
        [DbaInstance[]]$SqlInstance,
        [PSCredential]$SqlCredential,
        [Alias("Databases")]
        [object[]]$Database,
        [object[]]$ExcludeDatabase,
        [parameter(Position = 1, Mandatory = $false)]
        [int]$Threshold = 0,
        [parameter(Position = 2, Mandatory = $false)]
        [Alias("NoSystemDb")]
        [switch]$ExcludeSystemDb,
        [Alias('Silent')]
        [switch]$EnableException
    )

    begin {
        Test-DbaDeprecation -DeprecatedOn 1.0.0 -Parameter NoSystemDb

        $sql = ";WITH CT_DT AS
        (
            SELECT 'tinyint' AS DataType, 0 AS MinValue ,255 AS MaxValue UNION
            SELECT 'smallint' AS DataType, -32768 AS MinValue ,32767 AS MaxValue UNION
            SELECT 'int' AS DataType, -2147483648 AS MinValue ,2147483647 AS MaxValue UNION
            SELECT 'bigint' AS DataType, -9223372036854775808 AS MinValue ,9223372036854775807 AS MaxValue
        ), CTE_1
        AS
        (
          SELECT SCHEMA_NAME(o.schema_id) AS SchemaName,
                 OBJECT_NAME(a.Object_id) as TableName,
                 a.Name as ColumnName,
                 seed_value AS SeedValue,
                 CONVERT(bigint, increment_value) as IncrementValue,
 
                 CONVERT(bigint, ISNULL(a.last_value, seed_value)) AS LastValue,
 
                 (CASE
                        WHEN CONVERT(bigint, increment_value) < 0 THEN
                            (CONVERT(bigint, seed_value)
                            - CONVERT(bigint, ISNULL(last_value, seed_value))
                            + (CASE WHEN CONVERT(bigint, seed_value) <> 0 THEN ABS(CONVERT(bigint, increment_value)) ELSE 0 END))
                        ELSE
                            (CONVERT(bigint, ISNULL(last_value, seed_value))
                            - CONVERT(bigint, seed_value)
                            + (CASE WHEN CONVERT(bigint, seed_value) <> 0 THEN ABS(CONVERT(bigint, increment_value)) ELSE 0 END))
                    END) / ABS(CONVERT(bigint, increment_value)) AS NumberOfUses,
 
                  CAST (
                        (CASE
                            WHEN CONVERT(Numeric(20, 0), increment_value) < 0 THEN
                                ABS(CONVERT(Numeric(20, 0),dt.MinValue)
                                - CONVERT(Numeric(20, 0), seed_value)
                                - (CASE WHEN CONVERT(Numeric(20, 0), seed_value) <> 0 THEN ABS(CONVERT(Numeric(20, 0), increment_value)) ELSE 0 END))
                            ELSE
                                CONVERT(Numeric(20, 0),dt.MaxValue)
                                - CONVERT(Numeric(20, 0), seed_value)
                                + (CASE WHEN CONVERT(Numeric(20, 0), seed_value) <> 0 THEN ABS(CONVERT(Numeric(20, 0), increment_value)) ELSE 0 END)
                        END) / ABS(CONVERT(Numeric(20, 0), increment_value))
                    AS Numeric(20, 0)) AS MaxNumberRows
 
            FROM sys.identity_columns a
                INNER JOIN sys.objects o
                   ON a.object_id = o.object_id
                INNER JOIN sys.types As b
                     ON a.system_type_id = b.system_type_id
                INNER JOIN CT_DT dt
                     ON b.name = dt.DataType
          WHERE a.seed_value is not null
        ),
        CTE_2
        AS
        (
        SELECT SchemaName, TableName, ColumnName, CONVERT(BIGINT, SeedValue) AS SeedValue, CONVERT(BIGINT, IncrementValue) AS IncrementValue, LastValue, ABS(CONVERT(NUMERIC(20,0),MaxNumberRows)) AS MaxNumberRows, NumberOfUses,
               CONVERT(Numeric(18,2), ((CONVERT(Float, NumberOfUses) / ABS(CONVERT(Numeric(20, 0),MaxNumberRows)) * 100))) AS [PercentUsed]
          FROM CTE_1
        )
        SELECT DB_NAME() as DatabaseName, SchemaName, TableName, ColumnName, SeedValue, IncrementValue, LastValue, MaxNumberRows, NumberOfUses, [PercentUsed]
          FROM CTE_2"


        if ($Threshold -gt 0) {
            $sql += " WHERE [PercentUsed] >= " + $Threshold + " ORDER BY [PercentUsed] DESC"
        }
        else {
            $sql += " ORDER BY [PercentUsed] DESC"
        }
    }

    process {
        foreach ($instance in $SqlInstance) {
            Write-Message -Level Verbose -Message "Connecting to $instance"
            try {
                $server = Connect-SqlInstance -SqlInstance $instance -SqlCredential $SqlCredential -MinimumVersion 10
            }
            catch {
                Stop-Function -Message "Failure" -Category ConnectionError -ErrorRecord $_ -Target $instance -Continue
            }

            $dbs = $server.Databases

            if ($Database) {
                $dbs = $dbs | Where-Object Name -In $Database
            }

            if ($ExcludeDatabase) {
                $dbs = $dbs | Where-Object Name -NotIn $ExcludeDatabase
            }

            if ($ExcludeSystemDb) {
                $dbs = $dbs | Where-Object IsSystemObject -EQ $false
            }

            foreach ($db in $dbs) {
                Write-Message -Level Verbose -Message "Processing $db on $instance"

                if ($db.IsAccessible -eq $false) {
                    Stop-Function -Message "The database $db is not accessible. Skipping." -Continue
                }

                try {
                    $results = $db.Query($sql)
                }
                catch {
                    Stop-Function -Message "Error capturing data on $db" -Target $instance -ErrorRecord $_ -Exception $_.Exception -Continue
                }

                foreach ($row in $results) {
                    if ($row.PercentUsed -eq [System.DBNull]::Value) {
                        continue
                    }

                    if ($row.PercentUsed -ge $threshold) {
                        [PSCustomObject]@{
                            ComputerName   = $server.NetName
                            InstanceName   = $server.ServiceName
                            SqlInstance    = $server.DomainInstanceName
                            Database       = $row.DatabaseName
                            Schema         = $row.SchemaName
                            Table          = $row.TableName
                            Column         = $row.ColumnName
                            SeedValue      = $row.SeedValue
                            IncrementValue = $row.IncrementValue
                            LastValue      = $row.LastValue
                            MaxNumberRows  = $row.MaxNumberRows
                            NumberOfUses   = $row.NumberOfUses
                            PercentUsed    = $row.PercentUsed
                        } | Select-DefaultView -Exclude MaxNumberRows, NumberOfUses
                    }
                }
            }
        }
    }
}