Indexing services abstracts are the first 320 bytes of textual data in
Office documents or the contents of the description metatag for html
documents. If the html document does not have a description metatag, its the
first 320 bytes of the html document.

For sql you have to do something like this

declare @searchphrase varchar(20)

declare @MarkedupSearchPhrase varchar(20)

set @searchphrase='shadow'

set @MarkedupSearchPhrase ='<B>shadow</B>'

select --1,firstword=len(@searchphrase)-(len(substring(charcol,charindex(@se
archphrase,
charcol)-50,100))-charindex('shadow',substring(charcol,charindex(@searchphra
se, charcol)-50,100))),

--len(substring(charcol,charindex(@searchphrase, charcol)-50,100)),

MarkedUpColumn = case when len(charcol) >100 and
len(@searchphrase)-(len(substring(charcol,charindex(@searchphrase,
charcol)-50,100))-charindex(@SearchPhrase,substring(charcol,charindex(@searc
hphrase, charcol)-50,100))) <>-1 then
replace(ltrim(substring(replace(substring(charcol,charindex(@searchphrase,
charcol)-50,100),@searchphrase,@MarkedupSearchPhrase),1,len(replace(substrin
g(charcol,charindex(@searchphrase,
charcol)-50,100),@searchphrase,@MarkedupSearchPhrase))-
len(left(reverse(replace(substring(charcol,charindex(@searchphrase,
charcol)-50,100),@searchphrase,@MarkedupSearchPhrase)),charindex('
',reverse(replace(substring(charcol,charindex(@searchphrase,
charcol)-50,100),@searchphrase,@MarkedupSearchPhrase))))))),char(13)+char(10
),' ')

when len(charcol) >100 and
len(@searchphrase)-(len(substring(charcol,charindex(@searchphrase,
charcol)-50,100))-charindex(@SearchPhrase,substring(charcol,charindex(@searc
hphrase, charcol)-50,100))) =-1 then
replace(substring(charcol,charindex(@searchphrase,
charcol)-50,100),@searchphrase,@MarkedupSearchPhrase)

else replace(replace(substring(charcol,charindex(@searchphrase,
charcol)-50,100),@searchphrase,@MarkedupSearchPhrase),char(13)+char(10),' ')
end

from texttable where FreeText(*,@searchphrase)

this needs some more work as I have to correctly remove the first word or
word fragment in the markedupColumn (as long as its not the search phrase).
This also does inline hit highlighting.

For "true" abstracts like what indexing services delivers you should use the
left function.