SQL query optimization (Search) - sql

Question

I am trying to optimize a Stored procedure which is slow at the moment. It takes few parameters to search on which can be null. The query inside the SP looks like this.
SELECT
*some fields from the table*
FROM
[hrmCase]
WHERE
BrkId = #BrkId
AND
(ChannelId IN ('TO','TD'))
AND
case
when #PsId is null then 1
when (#PsId is not null) and ((SELECT SUBSTRING(UPPER(DATENAME(MONTH, Created)),1,3) + CAST(PSId AS varchar) PSId) like ('%' + #PsId + '%')) then 1 else 0
end = 1
AND
case
when #ACaseId is null then 1
when (#ACaseId is not null) and (AId like ('%' + #ACaseId + '%')) then 1 else 0
end = 1
AND
case
when #DateCreated is null then 1
when (#DateCreated is not null) and (dbo.StripTime(Created) = dbo.StripTime(#DateCreated)) then 1 else 0
end = 1
AND
case
when #Clients is null then 1
when (#Clients is not null) and (Client like ('%' + #Clients + '%')) then 1 else 0
end = 1
Is this the best way to do it or should I build a dynamic query based on the input parameters like below
Declare #SQLQuery AS NVarchar(4000)
Declare #ParamDefinition AS NVarchar(2000)
Set #SQLQuery = 'SELECT *some fields from the table* FROM [hrmCase] WHERE (1=1)'
If #PsId Is Not Null
Set #SQLQuery = #SQLQuery + ' And (SELECT SUBSTRING(UPPER(DATENAME(MONTH, Created)),1,3) + CAST(PSId AS varchar) PSId) like (''%''' + #PsId + '''%'')'
etc..
Which of the above two queries deemed more professional and will be quicker. Please suggest if there is a better way of doing the same thing.
Cheers,
DS

Answer 1

SQL Server is very bad at dealing with parameters like this--we've had many cases where we get it working acceptably and then 4 months later, something changes and it turns into table scans (or worse--I've seen performance FAR worse than simple table scans) all over again. (We have a 1.5TB database on SSD on mirrored 40 core servers). The best solution we've found is to use separate stored procedures or to use dynamic SQL. Many "experts" frown on dynamic SQL, but the reality is that in any decent environment these days, recompilation of dynamic SQL is insignificant in terms of CPU use and performance delay, and it eliminates the types of issues you're seeing because you eliminate the conditionals in the WHERE clauses that confuse the query optimizer.
The leading wildcards also will result in table scans in every case. Fulltext indexing can do this type of search much more efficiently than regular SQL. Some flavors of SQL Server support fulltext indexing and queries and some do not.