LOB compression + deduplication for query stats tables (#419)

Dashboard/Dashboard.csproj

@@ -6,10 +6,10 @@
     <UseWPF>true</UseWPF>
     <AssemblyName>PerformanceMonitorDashboard</AssemblyName>
     <Product>SQL Server Performance Monitor Dashboard</Product>
-    <Version>2.1.0</Version>
-    <AssemblyVersion>2.1.0.0</AssemblyVersion>
-    <FileVersion>2.1.0.0</FileVersion>
-    <InformationalVersion>2.1.0</InformationalVersion>
+    <Version>2.2.0</Version>
+    <AssemblyVersion>2.2.0.0</AssemblyVersion>
+    <FileVersion>2.2.0.0</FileVersion>
+    <InformationalVersion>2.2.0</InformationalVersion>
     <Company>Darling Data, LLC</Company>
     <Copyright>Copyright © 2026 Darling Data, LLC</Copyright>
     <ApplicationIcon>EDD.ico</ApplicationIcon>

Dashboard/Services/DatabaseService.QueryPerformance.cs

@@ -739,8 +739,8 @@ WITH per_lifetime AS
                 total_spills = MAX(qs.total_spills),
                 min_spills = MIN(qs.min_spills),
                 max_spills = MAX(qs.max_spills),
-                query_text = MAX(qs.query_text),
-                query_plan_text = MAX(qs.query_plan_text),
+                query_text = CAST(DECOMPRESS(MAX(qs.query_text)) AS nvarchar(max)),
+                query_plan_text = CAST(DECOMPRESS(MAX(qs.query_plan_text)) AS nvarchar(max)),
                 query_plan_hash = MAX(qs.query_plan_hash),
                 sql_handle = MAX(qs.sql_handle),
                 plan_handle = MAX(qs.plan_handle)
@@ -753,7 +753,7 @@ FROM collect.query_stats AS qs
                     OR (qs.last_execution_time >= @fromDate AND qs.last_execution_time <= @toDate)
                     OR (qs.creation_time <= @fromDate AND qs.last_execution_time >= @toDate)))
             )
-            AND qs.query_text NOT LIKE N'WAITFOR%'
+            AND CAST(DECOMPRESS(qs.query_text) AS nvarchar(max)) NOT LIKE N'WAITFOR%'
             GROUP BY
                 qs.database_name,
                 qs.query_hash,
@@ -922,7 +922,7 @@ WITH per_lifetime AS
                 total_spills = MAX(ps.total_spills),
                 min_spills = MIN(ps.min_spills),
                 max_spills = MAX(ps.max_spills),
-                query_plan_text = MAX(ps.query_plan_text),
+                query_plan_text = CAST(DECOMPRESS(MAX(ps.query_plan_text)) AS nvarchar(max)),
                 sql_handle = MAX(ps.sql_handle),
                 plan_handle = MAX(ps.plan_handle)
             FROM collect.procedure_stats AS ps
@@ -1101,7 +1101,7 @@ public async Task<List<QueryStoreItem>> GetQueryStoreDataAsync(int hoursBack = 2
             plan_type = MAX(qsd.plan_type),
             is_forced_plan = MAX(CONVERT(tinyint, qsd.is_forced_plan)),
             compatibility_level = MAX(qsd.compatibility_level),
-            query_sql_text = CONVERT(nvarchar(max), MAX(qsd.query_sql_text)),
+            query_sql_text = CAST(DECOMPRESS(MAX(qsd.query_sql_text)) AS nvarchar(max)),
             query_plan_hash = CONVERT(nvarchar(20), MAX(qsd.query_plan_hash), 1),
             force_failure_count = SUM(qsd.force_failure_count),
             last_force_failure_reason_desc = MAX(qsd.last_force_failure_reason_desc),
@@ -1121,7 +1121,7 @@ FROM collect.query_store_data AS qsd
                 OR (qsd.server_last_execution_time >= @fromDate AND qsd.server_last_execution_time <= @toDate)
                 OR (qsd.server_first_execution_time <= @fromDate AND qsd.server_last_execution_time >= @toDate)))
         )
-        AND qsd.query_sql_text NOT LIKE N'WAITFOR%'
+        AND CAST(DECOMPRESS(qsd.query_sql_text) AS nvarchar(max)) NOT LIKE N'WAITFOR%'
         GROUP BY
             qsd.database_name,
             qsd.query_id
@@ -2228,7 +2228,7 @@ ORDER BY
         SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
 
         SELECT
-            qsd.query_plan_text
+            CAST(DECOMPRESS(qsd.query_plan_text) AS nvarchar(max)) AS query_plan_text
         FROM collect.query_store_data AS qsd
         WHERE qsd.collection_id = @collection_id;";
 
@@ -2276,7 +2276,7 @@ FROM collect.procedure_stats AS ps
         SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
 
         SELECT
-            qs.query_plan_text
+            CAST(DECOMPRESS(qs.query_plan_text) AS nvarchar(max)) AS query_plan_text
         FROM collect.query_stats AS qs
         WHERE qs.collection_id = @collection_id;";
 

Installer/PerformanceMonitorInstaller.csproj

@@ -20,10 +20,10 @@
     <!-- Application metadata -->
     <AssemblyName>PerformanceMonitorInstaller</AssemblyName>
     <Product>SQL Server Performance Monitor Installer</Product>
-    <Version>2.1.0</Version>
-    <AssemblyVersion>2.1.0.0</AssemblyVersion>
-    <FileVersion>2.1.0.0</FileVersion>
-    <InformationalVersion>2.1.0</InformationalVersion>
+    <Version>2.2.0</Version>
+    <AssemblyVersion>2.2.0.0</AssemblyVersion>
+    <FileVersion>2.2.0.0</FileVersion>
+    <InformationalVersion>2.2.0</InformationalVersion>
     <Company>Darling Data, LLC</Company>
     <Copyright>Copyright © 2026 Darling Data, LLC</Copyright>
     <Description>Installation utility for SQL Server Performance Monitor - Supports SQL Server 2016-2025</Description>

InstallerGui/InstallerGui.csproj

@@ -8,10 +8,10 @@
     <AssemblyName>PerformanceMonitorInstallerGui</AssemblyName>
     <RootNamespace>PerformanceMonitorInstallerGui</RootNamespace>
     <Product>SQL Server Performance Monitor Installer</Product>
-    <Version>2.1.0</Version>
-    <AssemblyVersion>2.1.0.0</AssemblyVersion>
-    <FileVersion>2.1.0.0</FileVersion>
-    <InformationalVersion>2.1.0</InformationalVersion>
+    <Version>2.2.0</Version>
+    <AssemblyVersion>2.2.0.0</AssemblyVersion>
+    <FileVersion>2.2.0.0</FileVersion>
+    <InformationalVersion>2.2.0</InformationalVersion>
     <Company>Darling Data, LLC</Company>
     <Copyright>Copyright © 2026 Darling Data, LLC</Copyright>
     <ApplicationIcon>EDD.ico</ApplicationIcon>

Lite/PerformanceMonitorLite.csproj

@@ -7,10 +7,10 @@
     <AssemblyName>PerformanceMonitorLite</AssemblyName>
     <RootNamespace>PerformanceMonitorLite</RootNamespace>
     <Product>SQL Server Performance Monitor Lite</Product>
-    <Version>2.1.0</Version>
-    <AssemblyVersion>2.1.0.0</AssemblyVersion>
-    <FileVersion>2.1.0.0</FileVersion>
-    <InformationalVersion>2.1.0</InformationalVersion>
+    <Version>2.2.0</Version>
+    <AssemblyVersion>2.2.0.0</AssemblyVersion>
+    <FileVersion>2.2.0.0</FileVersion>
+    <InformationalVersion>2.2.0</InformationalVersion>
     <Company>Darling Data, LLC</Company>
     <Copyright>Copyright © 2026 Darling Data, LLC</Copyright>
     <Description>Lightweight SQL Server performance monitoring - no installation required on target servers</Description>

install/01_install_database.sql

@@ -274,6 +274,10 @@ BEGIN
             DEFAULT 5,
         retention_days integer NOT NULL
             DEFAULT 30,
+        collect_query bit NOT NULL
+            DEFAULT CONVERT(bit, 'true'),
+        collect_plan bit NOT NULL
+            DEFAULT CONVERT(bit, 'true'),
         [description] nvarchar(500) NULL,
         created_date datetime2(7) NOT NULL
             DEFAULT SYSDATETIME(),

install/02_create_tables.sql

@@ -168,10 +168,11 @@ BEGIN
             total_worker_time_delta /
               NULLIF(sample_interval_seconds, 0) / 1000.
         ),
-        /*Query text and execution plan*/
-        query_text nvarchar(MAX) NULL,
-        query_plan_text nvarchar(MAX) NULL,
-        query_plan xml NULL,
+        /*Query text and execution plan (compressed with COMPRESS/DECOMPRESS)*/
+        query_text varbinary(max) NULL,
+        query_plan_text varbinary(max) NULL,
+        /*Deduplication hash for skipping unchanged rows*/
+        row_hash binary(32) NULL,
         CONSTRAINT
             PK_query_stats
         PRIMARY KEY CLUSTERED
@@ -183,6 +184,34 @@ BEGIN
     PRINT 'Created collect.query_stats table';
 END;
 
+/*
+2b. Query Stats Dedup Tracking
+One row per natural key, updated on each collection cycle
+*/
+IF OBJECT_ID(N'collect.query_stats_latest_hash', N'U') IS NULL
+BEGIN
+    CREATE TABLE
+        collect.query_stats_latest_hash
+    (
+        sql_handle varbinary(64) NOT NULL,
+        statement_start_offset integer NOT NULL,
+        statement_end_offset integer NOT NULL,
+        plan_handle varbinary(64) NOT NULL,
+        row_hash binary(32) NOT NULL,
+        last_seen datetime2(7) NOT NULL
+            DEFAULT SYSDATETIME(),
+        CONSTRAINT
+            PK_query_stats_latest_hash
+        PRIMARY KEY CLUSTERED
+            (sql_handle, statement_start_offset,
+             statement_end_offset, plan_handle)
+        WITH
+            (DATA_COMPRESSION = PAGE)
+    );
+
+    PRINT 'Created collect.query_stats_latest_hash table';
+END;
+
 /*
 3. Memory Pressure
 */
@@ -429,9 +458,10 @@ BEGIN
             total_worker_time_delta /
               NULLIF(sample_interval_seconds, 0) / 1000.
         ),
-        /*Execution plan*/
-        query_plan_text nvarchar(max) NULL,
-        query_plan xml NULL,
+        /*Execution plan (compressed with COMPRESS/DECOMPRESS)*/
+        query_plan_text varbinary(max) NULL,
+        /*Deduplication hash for skipping unchanged rows*/
+        row_hash binary(32) NULL,
         CONSTRAINT
             PK_procedure_stats
         PRIMARY KEY CLUSTERED
@@ -443,6 +473,32 @@ BEGIN
     PRINT 'Created collect.procedure_stats table';
 END;
 
+/*
+9b. Procedure Stats Dedup Tracking
+One row per natural key, updated on each collection cycle
+*/
+IF OBJECT_ID(N'collect.procedure_stats_latest_hash', N'U') IS NULL
+BEGIN
+    CREATE TABLE
+        collect.procedure_stats_latest_hash
+    (
+        database_name sysname NOT NULL,
+        object_id integer NOT NULL,
+        plan_handle varbinary(64) NOT NULL,
+        row_hash binary(32) NOT NULL,
+        last_seen datetime2(7) NOT NULL
+            DEFAULT SYSDATETIME(),
+        CONSTRAINT
+            PK_procedure_stats_latest_hash
+        PRIMARY KEY CLUSTERED
+            (database_name, object_id, plan_handle)
+        WITH
+            (DATA_COMPRESSION = PAGE)
+    );
+
+    PRINT 'Created collect.procedure_stats_latest_hash table';
+END;
+
 /*
 10. Currently Executing Query Snapshots
 Table is created dynamically by sp_WhoIsActive on first collection
@@ -473,7 +529,7 @@ BEGIN
         server_first_execution_time datetime2(7) NOT NULL,
         server_last_execution_time datetime2(7) NOT NULL,
         module_name nvarchar(261) NULL,
-        query_sql_text nvarchar(max) NULL,
+        query_sql_text varbinary(max) NULL,
         query_hash binary(8) NULL,
         /*Execution count*/
         count_executions bigint NOT NULL,
@@ -531,9 +587,11 @@ BEGIN
         last_force_failure_reason_desc nvarchar(128) NULL,
         plan_forcing_type nvarchar(60) NULL,
         compatibility_level smallint NULL,
-        query_plan_text nvarchar(max) NULL,
-        compilation_metrics xml NULL,
+        query_plan_text varbinary(max) NULL,
+        compilation_metrics varbinary(max) NULL,
         query_plan_hash binary(8) NULL,
+        /*Deduplication hash for skipping unchanged rows*/
+        row_hash binary(32) NULL,
         CONSTRAINT
             PK_query_store_data
         PRIMARY KEY CLUSTERED
@@ -545,6 +603,32 @@ BEGIN
     PRINT 'Created collect.query_store_data table';
 END;
 
+/*
+11b. Query Store Data Dedup Tracking
+One row per natural key, updated on each collection cycle
+*/
+IF OBJECT_ID(N'collect.query_store_data_latest_hash', N'U') IS NULL
+BEGIN
+    CREATE TABLE
+        collect.query_store_data_latest_hash
+    (
+        database_name sysname NOT NULL,
+        query_id bigint NOT NULL,
+        plan_id bigint NOT NULL,
+        row_hash binary(32) NOT NULL,
+        last_seen datetime2(7) NOT NULL
+            DEFAULT SYSDATETIME(),
+        CONSTRAINT
+            PK_query_store_data_latest_hash
+        PRIMARY KEY CLUSTERED
+            (database_name, query_id, plan_id)
+        WITH
+            (DATA_COMPRESSION = PAGE)
+    );
+
+    PRINT 'Created collect.query_store_data_latest_hash table';
+END;
+
 /*
 Trace analysis table - stores processed trace file data
 */

install/06_ensure_collection_table.sql

@@ -265,10 +265,11 @@ BEGIN
             total_worker_time_delta /
               NULLIF(sample_interval_seconds, 0) / 1000.
         ),
-        /*Query text and execution plan*/
-        query_text nvarchar(max) NULL,
-        query_plan_text nvarchar(max) NULL,
-        query_plan xml NULL,
+        /*Query text and execution plan (compressed with COMPRESS/DECOMPRESS)*/
+        query_text varbinary(max) NULL,
+        query_plan_text varbinary(max) NULL,
+        /*Deduplication hash for skipping unchanged rows*/
+        row_hash binary(32) NULL,
         CONSTRAINT
             PK_query_stats
         PRIMARY KEY CLUSTERED
@@ -446,9 +447,10 @@ BEGIN
             total_worker_time_delta /
               NULLIF(sample_interval_seconds, 0) / 1000.
         ),
-        /*Execution plan*/
-        query_plan_text nvarchar(max) NULL,
-        query_plan xml NULL,
+        /*Execution plan (compressed with COMPRESS/DECOMPRESS)*/
+        query_plan_text varbinary(max) NULL,
+        /*Deduplication hash for skipping unchanged rows*/
+        row_hash binary(32) NULL,
         CONSTRAINT
             PK_procedure_stats
         PRIMARY KEY CLUSTERED
@@ -491,7 +493,7 @@ BEGIN
         server_first_execution_time datetime2(7) NOT NULL,
         server_last_execution_time datetime2(7) NOT NULL,
         module_name nvarchar(261) NULL,
-        query_sql_text nvarchar(max) NULL,
+        query_sql_text varbinary(max) NULL,
         query_hash binary(8) NULL,
         /*Execution count*/
         count_executions bigint NOT NULL,
@@ -549,9 +551,11 @@ BEGIN
         last_force_failure_reason_desc nvarchar(128) NULL,
         plan_forcing_type nvarchar(60) NULL,
         compatibility_level smallint NULL,
-        query_plan_text nvarchar(max) NULL,
-        compilation_metrics xml NULL,
+        query_plan_text varbinary(max) NULL,
+        compilation_metrics varbinary(max) NULL,
         query_plan_hash binary(8) NULL,
+        /*Deduplication hash for skipping unchanged rows*/
+        row_hash binary(32) NULL,
         CONSTRAINT
             PK_query_store_data
         PRIMARY KEY CLUSTERED