Best way to optimize this SQL Query - sql

Question

I have to optimize this query and I am really in a hurry here. The following query searches by client. The input value RIF.keyvaluechar
LIKE 'V%10553790 ' is because in some old registers in the database some IDs when missing characters it used to be V0012345678 but it should have been V12345678 as that's the maximum amount of characters the ID can have. I know 12345678 should have been numeric and the V a char and then compare, but that's another issue.
Anyway, the query is this one:
SELECT DISTINCT idata.itemnum AS [ID],
LTRIM(RTRIM(ISNULL(CONTRATO.keyvaluechar,'N/A'))) AS [Contrato],
idata.datestored AS [Fecha],
NUMERO.keyvaluesmall AS [Numero],
TIPO.keyvaluechar AS [Tipo],
LTRIM(RTRIM(ISNULL(LC.lifecyclename,'N/A'))) AS [Flujo],
LTRIM(RTRIM(ISNULL(LC.lcnum,-1))) AS [FlujoID],
LTRIM(RTRIM(ISNULL(LCS.statename,'N/A'))) AS [Cola],
LTRIM(RTRIM(ISNULL(LCS.statenum,-1))) AS [ColaID],
CASE
WHEN PC.NombreProceso IN('PTD','PV2','PV3') THEN 1
ELSE 0
END AS [Portada]
FROM OnBase.hsi.itemdata idata WITH (NOLOCK)
INNER JOIN OnBase.hsi.keyitem109 TIPO WITH (NOLOCK) ON TIPO.itemnum = idata.itemnum
INNER JOIN OnBase.hsi.keyitem113 NUMERO WITH (NOLOCK) ON NUMERO.itemnum = idata.itemnum
LEFT JOIN OnBase.hsi.keyitem132 CONTRATO WITH (NOLOCK) ON CONTRATO.itemnum = idata.itemnum
LEFT JOIN OnBase.hsi.keyitem114 CLIENTE WITH (NOLOCK) ON CLIENTE.itemnum = idata.itemnum
LEFT JOIN OnBase.hsi.keyitem111 RIF WITH (NOLOCK) ON RIF.itemnum = idata.itemnum
INNER JOIN OnBase.hsi.doctype DOC WITH (NOLOCK) ON DOC.itemtypenum = idata.itemtypenum
INNER JOIN BD_WorkFlow.dbo.BBVA_ProcesosConfig PC WITH (NOLOCK) ON PC.ID_Documento = idata.itemtypenum
LEFT JOIN Onbase.hsi.itemlc ILC WITH (NOLOCK) ON ILC.itemnum = idata.itemnum
LEFT JOIN Onbase.hsi.lcstate LCS WITH (NOLOCK) ON LCS.statenum = ILC.statenum
LEFT JOIN Onbase.hsi.lifecycle LC WITH (NOLOCK) ON LC.lcnum = ILC.lcnum
WHERE PC.NombreProceso <> 'XXX' AND
PC.NombreProceso NOT IN('PTD','PV2','PV3') AND
TIPO.keyvaluechar = 'CCD' AND
RIF.keyvaluechar LIKE 'V%10553790 '
As you can see it is this way so it finds V0012345678 or V12345678 but this is not the right way or I feel it is the best optimization, although I am no expert in databases.
Anyways, I've though about something like this instead of last line
AND LEFT ('RIF.Keyvaluechar, 1) ="V"
AND SUBSTRING (RIF.Keyvaluechar, 2, LEN(RIF.Keyvaluechar)) = "12345678"
What do you guys think? Is there any other better way to improve upon this?

Answer 1

First, your query has a logic problem. You have this:
LEFT JOIN OnBase.hsi.keyitem111 RIF WITH(NOLOCK) ON RIF.itemnum = idata.itemnum
and then this in your where clause:
AND RIF.keyvaluechar LIKE 'V%10553790 '
Putting that filter in your where clause effectively changes your left join to an inner join. To fix this, move the filter to the join.
In terms of optimizing it, I assume that means to make it run faster. What you were thinking about will probably slow things down because you are filtering on function results instead of fields. A better approach, no matter how much of a hurry you are in, is to look at the indexes in your database and try to filter on those. In fact, it might be appropriate to add new ones.

Answer 2

Is the Keyvaluechar always a number from the second character onwards and you want to treat it as a number (=remove leading zeros). You could try to add a persisted column convert(int, SUBSTRING (Keyvaluechar, 2, 10)) to the table, then index that, and use it as a search criteria. At least I would assume that should help a lot.
In addition to that, looking at statistics IO output might be a good idea too, to see what table is actually responsible for the biggest I/O amounts.
Just a note, I hope you also know the problems using NOLOCK can cause you.