REGEXP slow for temporary tables

Hi,

I have encountered a problem with REGEXP being extremely slow when used in query to temporary table.

While this query

select count(*) from dbo.sysobjects where name regexp '.*'

returns 62,000 in a few miliseconds,

this one, limited to just 1000 rows

select top 1000 name into #names from dbo.sysobjects
select count(*) from #names where name regexp '.*'

takes 20 seconds to return.

The SAP IQ version is
SAP IQ/16.1.050.1886/10820/P/SP05.01/Linux/Linux64 – x86_64 – 3.10.0-327/64bit/2021-12-07 02:58:37

Does anyone has any explanation and perhaps a solution?

Best regards, Martin