Hi,
isql shows 1 msec as the execution time for a simple query (output is copied below; it is a fresh copy of virtuoso with no data loaded)
query:
sparql select * where {?s ?p ?o} limit 1;
#########################################################################
./isql 1111 dba dba …/…/q1
OpenLink Virtuoso Interactive SQL (Virtuoso)
Version 07.20.3230 as of Mar 1 2020
Type HELP; for help and EXIT; to exit.
Connected to OpenLink Virtuoso
Driver: 07.20.3230 OpenLink Virtuoso ODBC Driver
s p o
LONG VARCHAR LONG VARCHAR LONG VARCHAR
h tt p://w ww .openlinksw. com / virtr df-data-for ma ts#de fault -iid h tt p:/ /www .w3. org/1999/ 02/22-rdf-syntax-ns#type http:/ /www .openli nksw .com /sch emas/vi rtrdf# QuadMapFo rmat
1 Rows. – 1 msec.
#########################################################################
but when I run the same query and calculate the run-time using the OS tools, the calculated execution time is more (my OS commands and the output is copied)
ts=$(date +%s%N) ; ./isql 1111 dba dba …/…/q1 ; tt=$((($(date +%s%N) - $ts)/1000000)) ; echo “Time taken: $tt milliseconds”
OpenLink Virtuoso Interactive SQL (Virtuoso)
Version 07.20.3230 as of Mar 1 2020
Type HELP; for help and EXIT; to exit.
Connected to OpenLink Virtuoso
Driver: 07.20.3230 OpenLink Virtuoso ODBC Driver
s p o
LONG VARCHAR LONG VARCHAR LONG VARCHAR
http /www .ope nlinksw. com/virtrdf -data-formats#default-iid h t tp
/www .w3 .org/1999/02/22-rdf-syntax-ns#type htt p
/www. o penlin ksw. com/schemas/virtrdf#Quad MapFormat
1 Rows. – 1 msec.
Time taken: 11 milliseconds
#########################################################################
It would be great if Virtuoso’s experts (eg, @imikhailov) could answer the following questions:
- What might be the probable reasons behind these execution time differences? (did I make a mistake?)
- Would you please explain (in further details) that how exactly the query execution time is calculated and outputted in virtuoso (i.e., isql’s query execution time breakdown)?
Thanks
(P. S.: I did not use any emojis, but added some extra spaces between above URIs, because the website does not allow me to create a topic with more than two links)