This function produces representative samples for use in displaying a query hit. There are two modes: html mode and text mode. In html mode everything looks like html tags is ignored and searching of excerpt begins from <body> tag. All found hit words highlighted by html_hit_tag.
In text mode text is treated as plain text, html tag detection is disabled and hit words is not highlighted.
varchar
creates a search excerpt from found DAV resource
for select RES_CONTENT from WS.WS.SYS_DAV_RES
where contains (RES_CONTENT, 'place and knowledge')
do {
http_value (search_excerpt (vector ('place', 'knowledge'),
cast (RES_CONTENT as varchar),
200000, 90, 200, 'b', 1),
'P');
}