We got a bug report here geany/geany-osx#42 (comment) in Geany where Geany stopped responding for very long time for not so large SQL file (~16000 LOCs). I bisected this problem to this commit:

4dbda62

Basically the problem isn't the commit itself but rather that string which is passed to this function and which should contain just the current token seems to contain a huge amount of the SQL code and not just a single token (I haven't checked the size but it certainly is hundreds of characters long). As this string is getting bigger, lookupCaseKeyword() is called every time a charactger is added in

if (empty_tag
    && KEYWORD_inquiry_directive == lookupCaseKeyword (vStringValue (string), Lang_sql))

which consumes a lot of time. A simple workaround which reduces the parsing time significantly is to check the size of the string against some constant corresponding to the longest keyword:

if (empty_tag && string->length < 20
    && KEYWORD_inquiry_directive == lookupCaseKeyword (vStringValue (string), Lang_sql))

Still, it would be good to investigate what the reason behind the long token is and fix it properly.

I assume that @cloudis-ild could send the file causing this issue privately or I could send it as well if he agrees.