¿Cómo puedo destruir este XML de eventos extendidos lo más rápido posible?

Creé una sesión de eventos extendidos en SQL Server 2008 R2. La sesión se ejecuta y recopila eventos a medida que ocurren, exactamente como se esperaría.

Si destruyo el xml cuando hay relativamente pocos eventos, el rendimiento es aceptable. Cuando tengo miles de eventos, se necesita para siempre destruir el xml.

Sé que estoy haciendo algo mal, simplemente no tengo suficiente conocimiento sobre las partes internas del motor XML para entender qué.

Esta es la definición de mi sesión de eventos extendidos:

IF EXISTS 
(
    SELECT 1 
    FROM sys.server_event_sessions dxs 
    WHERE dxs.name = 'queries'
)
BEGIN
    IF EXISTS (
        SELECT 1 
        FROM sys.dm_xe_sessions dxs 
        WHERE dxs.name = 'queries'
    )
    BEGIN
        ALTER EVENT SESSION queries ON SERVER STATE = STOP;
    END
    DROP EVENT SESSION queries ON SERVER;
END

CREATE EVENT SESSION queries ON SERVER 
ADD EVENT sqlserver.sql_statement_starting
(
    ACTION 
    (
        package0.collect_system_time
        --, package0.event_sequence
        , sqlserver.client_app_name
        , sqlserver.client_hostname
        --, sqlserver.database_name
        , sqlserver.plan_handle
        , sqlserver.sql_text
        , sqlserver.username
    )
    WHERE sqlserver.username = N'<some username>'
        AND sqlserver.database_id = 6 /* specific database */
        AND sqlserver.client_hostname <> '<my machine>'
) 
, ADD EVENT sqlserver.error_reported 
(
    ACTION 
    (
        package0.collect_system_time
        , sqlserver.client_app_name
        , sqlserver.client_hostname
        , sqlserver.plan_handle
        , sqlserver.sql_text
        , sqlserver.username
    )
    WHERE sqlserver.username <> N'<some username>'
        /* fluff errors below */
        AND error <> 5703 /* Changed language setting to %.*ls. */
        AND error <> 5701 /* Changed database context to '%.*ls'. */
        AND error <> 2528 /* DBCC execution completed. If DBCC printed error messages, contact your system administrator. */
        AND error <> 7969 /* No active open transactions. */
        --AND error <> 14205/* (unknown) */
        AND error <> 4035 /* Processed %I64d pages for database '%ls', file '%ls' on file %d. */
        AND error <> 18265/* Log was backed up. Database: %s, creation date(time): %s(%s), first LSN: %s, last LSN: %s, number of dump devices: %d, device information: (%s). This is an informational message only. No user action is required. */
        AND error <> 3014 /* %hs successfully processed %I64d pages in %d.%03d seconds (%d.%03d MB/sec). */
        AND error <> 14570/* (Job outcome) */
        AND error <> 8153 /* Warning: Null value is eliminated by an aggregate or other SET operation. */

)
ADD TARGET package0.ring_buffer
(
    SET max_memory = 102400
)
WITH 
(
    STARTUP_STATE=OFF
    , TRACK_CAUSALITY = ON
);
GO

IF EXISTS 
(
    SELECT 1 
    FROM sys.server_event_sessions dxs 
    WHERE dxs.name = 'queries'
)
BEGIN
    ALTER EVENT SESSION queries ON SERVER STATE = START;
END

Así es como estoy triturando los resultados:

/***************************

shred the Event Data into readable form

***************************/

DECLARE @xml XML;

SELECT TOP(1) @xml = CONVERT(xml, xet.target_data)
FROM sys.dm_xe_session_targets AS xet
    INNER JOIN sys.dm_xe_sessions AS xe ON (xe.address = xet.event_session_address)
WHERE xe.name = 'queries';

SELECT t.EventName
    , DateStamp = DATEADD(HOUR, -6, t.EventDateStamp)
    , DatabaseName = d.name
    , t.ErrorNumber
    , t.ErrorSeverity
    , t.ErrorState
    , t.ErrorMessage
    , t.CollectSystemTime
    , t.ClientAppName
    , t.ClientHostName
    , t.PlanHandle
    , t.SqlText
    , t.UserName
FROM (
        SELECT EventName = s.value('(@name)[1]','varchar(500)')
            , EventDateStamp = s.value('(@timestamp)[1]','datetime')
            , DatabaseID = s.value('(data[(@name)[1] eq "source_database_id"]/value/text())[1]','varchar(255)')
            , ErrorNumber = s.value('(data[(@name)[1] eq "error"]/value/text())[1]','int')
            , ErrorSeverity = s.value('(data[(@name)[1] eq "severity"]/value/text())[1]','int')
            , ErrorState = s.value('(data[(@name)[1] eq "state"]/value/text())[1]','int')
            , ErrorMessage = s.value('(data[(@name)[1] eq "message"]/value/text())[1]','varchar(255)')
            , CollectSystemTime = s.value('(action[(@name)[1] eq "collect_system_time"]/text/text())[1]','varchar(255)')
            , ClientAppName = s.value('(action[(@name)[1] eq "client_app_name"]/value/text())[1]','varchar(255)')
            , ClientHostName = s.value('(action[(@name)[1] eq "client_hostname"]/value/text())[1]','varchar(255)')
            , PlanHandle = CONVERT(xml, s.value('(action[(@name)[1] eq "plan_handle"]/value/text())[1]','varchar(255)')).value('(plan/@handle)[1]', 'varchar(255)')
            , SqlText = s.value('(action[(@name)[1] eq "sql_text"]/value/text())[1]','nvarchar(max)')
            , UserName = s.value('(action[(@name)[1] eq "username"]/value/text())[1]','varchar(128)')
        FROM @xml.nodes('/RingBufferTarget/event') AS xm(s)
    ) t
    LEFT JOIN sys.databases d ON t.DatabaseID = d.database_id
ORDER BY t.UserName
    , t.EventDateStamp;

Gracias a @Tom V por identificar esta publicación de blog que identifica la necesidad de una tabla temporal.

Adaptando las ideas en la publicación del blog, esto ahora funciona muy rápidamente:

/***************************

shred the Event Data into readable form

***************************/

DECLARE @xml XML;

SELECT TOP(1) @xml = CONVERT(xml, xet.target_data)
FROM sys.dm_xe_session_targets AS xet
    INNER JOIN sys.dm_xe_sessions AS xe ON (xe.address = xet.event_session_address)
WHERE xe.name = 'queries';

IF OBJECT_ID('tempdb..#xmlResults') IS NOT NULL
DROP TABLE #xmlResults;

CREATE TABLE #xmlResults
(
    RowNum INT NOT NULL
        PRIMARY KEY CLUSTERED
        IDENTITY(1,1)
    , xeXML XML NOT NULL
);

INSERT INTO #xmlResults (xeXML)
SELECT xm.s.query('.')
FROM @xml.nodes('/RingBufferTarget/event') AS xm(s)
OPTION (Optimize FOR (@xml = Null)); -- Useful for SQL 2008

SELECT *
FROM #xmlResults

SELECT t.EventName
    , DateStamp = DATEADD(HOUR, -6, t.EventDateStamp)
    , DatabaseName = d.name
    , t.ErrorNumber
    , t.ErrorSeverity
    , t.ErrorState
    , t.ErrorMessage
    , t.CollectSystemTime
    , t.ClientAppName
    , t.ClientHostName
    , t.PlanHandle
    , t.SqlText
    , t.UserName
FROM (
        SELECT EventName =          xeXML.value('(event/@name)[1]','varchar(500)')
            , EventDateStamp =      xeXML.value('(event/@timestamp)[1]','datetime')
            , DatabaseID =          xeXML.value('(event/data[(@name)[1] eq "source_database_id"]/value/text())[1]','varchar(255)')
            , ErrorNumber =         xeXML.value('(event/data[(@name)[1] eq "error"]/value/text())[1]','varchar(255)')
            , ErrorSeverity =       xeXML.value('(event/data[(@name)[1] eq "severity"]/value/text())[1]','varchar(255)')
            , ErrorState =          xeXML.value('(event/data[(@name)[1] eq "state"]/value/text())[1]','varchar(255)')
            , ErrorMessage =        xeXML.value('(event/data[(@name)[1] eq "message"]/value/text())[1]','varchar(255)')
            , CollectSystemTime =   xeXML.value('(event/action[(@name)[1] eq "collect_system_time"]/text/text())[1]','varchar(255)')
            , ClientAppName =       xeXML.value('(event/action[(@name)[1] eq "client_app_name"]/value/text())[1]','varchar(255)')
            , ClientHostName =      xeXML.value('(event/action[(@name)[1] eq "client_hostname"]/value/text())[1]','varchar(255)')
            , PlanHandle = CONVERT(xml, xeXML.value('(event/action[(@name)[1] eq "plan_handle"]/value/text())[1]','varchar(255)')).value('(plan/@handle)[1]', 'varchar(255)')
            , SqlText =             xeXML.value('(event/action[(@name)[1] eq "sql_text"]/value/text())[1]','nvarchar(max)')
            , UserName =            xeXML.value('(event/action[(@name)[1] eq "username"]/value/text())[1]','varchar(128)')
        FROM #xmlResults xm
    ) t
    LEFT JOIN sys.databases d ON t.DatabaseID = d.database_id
ORDER BY t.UserName
    , t.EventDateStamp;