Re: Query never returns ...

Stephan,

Here is what EXPLAIN shows:

NOTICE:  QUERY PLAN:

Sort  (cost=0.02..0.02 rows=1 width=64)
  ->  Nested Loop  (cost=0.00..0.01 rows=1 width=64)
        ->  Seq Scan on tblmedcond  (cost=0.00..0.00 rows=1 width=36)
        ->  Seq Scan on tblsidedruglink  (cost=0.00..0.00 rows=1 width=28)

As for vacuum analyze - prior to running into these problems, I deleted
all data from the database (using delete from <tblname>) and then ran
vacuumdb -a, after which I loaded the data into the tables using 'copy
... from' - there have been no updates to the database since then -
merely selects.

-Brice

Stephan Szabo wrote:
>
> What does explain show for the query and have you run
> vacuum analyze recently on the tables?
>
> On Thu, 8 Feb 2001, Brice Ruth wrote:
>
> > The following query:
> >
> > SELECT
> >       tblSIDEDrugLink.DrugID,
> >       tblSIDEDrugLink.MedCondID,
> >       tblMedCond.PatientName AS MedCondPatientName,
> >       tblMedCond.ProfessionalName AS MedCondProfessionalName,
> >       tblSIDEDrugLink.Frequency,
> >       tblSIDEDrugLink.SeverityLevel
> > FROM
> >       tblSIDEDrugLink,
> >       tblMedCond
> > WHERE
> >       (tblSIDEDrugLink.DrugID IN ('DG-18698')) AND
> >       (tblSIDEDrugLink.MedCondID = tblMedCond.MedCondID)
> > ORDER BY
> >       tblSIDEDrugLink.DrugID,
> >       tblSIDEDrugLink.Frequency,
> >       tblSIDEDrugLink.SeverityLevel,
> >       tblSIDEDrugLink.MedCondID;
> >
> > seems to not be liked by PostgreSQL.  Table 'tblSIDEDrugLink' has the
> > following structure:
> >
> > CREATE TABLE TBLSIDEDRUGLINK
> > (
> >     DRUGID                      VARCHAR(10) NOT NULL,
> >     MEDCONDID                   VARCHAR(10) NOT NULL,
> >     FREQUENCY                   INT2,
> >     SEVERITYLEVEL               INT2,
> >     CONSTRAINT PK_TBLSIDEDRUGLINK PRIMARY KEY (DRUGID, MEDCONDID)
> > );
> >
> > with the following index:
> > CREATE INDEX IX_TBLSIDEDRUGLINK1 ON TBLSIDEDRUGLINK (MEDCONDID);
> >
> > This table has 153,288 rows.
> >
> > Table 'tblMedCond' has the following structure:
> >
> > CREATE TABLE TBLMEDCOND
> > (
> >     MEDCONDID                   VARCHAR(10) NOT NULL,
> >     PROFESSIONALNAME            VARCHAR(58),
> >     PATIENTNAME                 VARCHAR(58),
> >     CONSTRAINT PK_TBLMEDCOND PRIMARY KEY (MEDCONDID)
> > );
> >
> > This table has 1,730 rows.
> >
> > The query above is made by a third-party API that I don't have the
> > source for, so I can't modify the query in the API, though the
> > third-party has been quite willing to help out - they may even ship me a
> > 'special' version of the API if there's something in this query that
> > PostgreSQL for some reason doesn't implement efficiently enough.
> >
> > If it would help anyone to see the query plan or such - I can modify the
> > logs to show that, just let me know.
> >
> > Btw - I've let this query run for a while & I haven't seen it complete
> > ... soooo ... I don't know if it would ever complete or not.
> >
> > Any help at all is as always, appreciated.
> >
> > Sincerest regards,
> > --
> > Brice Ruth
> > WebProjkt, Inc.
> > VP, Director of Internet Technology
> > http://www.webprojkt.com/
> >

--
Brice Ruth
WebProjkt, Inc.
VP, Director of Internet Technology
http://www.webprojkt.com/