[SQL] Number of rows in a cursor ?
Hi ... Is it possible to get the total number of rows found in a cursor, or must I make a count(*) and then a select ? /BL ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [SQL] Number of rows in a cursor ?
Bo Lorentsen wrote: Is it possible to get the total number of rows found in a cursor, or must I make a count(*) and then a select ? Perhaps: GET DIAGNOSTICS rc = ROW_COUNT; (see http://archives.postgresql.org/pgsql-novice/2003-06/msg00143.php and http://www.postgresql.org/docs/8.0/interactive/plpgsql-statements.html#PLPGSQL-STATEMENTS-DIAGNOSTICS) /Thomas. ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [SQL] Tuple insert missing query in ongoing transaction
Dear DAQ, Thanks for the native answer ;) For those who have concerns reading Hungarian, here is an excerpt including my answer. You adviced me to issue an ACCESS EXCLUSIVE lock on table "shift" in transaction B, before issuing the actual insert, so that the insert will wait till the end of transaction S. Actually, you pointed me to the right way of the PostgreSQL doc and gave me the inspiration to actually read about lock modes :) As far as I understood things: 1. Shouldn't it be enough to lock in EXCLUSIVE mode, thus allowing others to access (select only) table "shift"? What's more, since any ins/upd/del on a table aquires ROW EXCLUSIVE mode, shouldn't it be enough to just acquire SHARE mode? It wouldn't even conflict with concurrent SHARE locks of other clients inserting into table B. 2. Am I reading right that acquiring a lock in a BEFORE trigger is too late? (not mentioning that trigger firing order is undefined) If so, is there another way to provide a server-side automatic lock before the insert, say, writing an ON INSERT rule on table "barcode"? 3. I can't see why shouldn't this work with updates and deletes (on any of the two tables), but since I'm new to this topic, it's better to ask: should I have any further concerns? TIA, -- G. On 2005.08.23. 18:26, daq wrote: SG> Dear Gurus, SG> I know this is the typical case of transaction use, I just seem to lack the SG> appropriate education of what exactly happens and whether I may be able to SG> detect it. SG> I have two queries, one affecting the other. SG> 1. INSERT INTO barcode. SG> A BEFORE INSERT/UPDATE trigger checks if there's an appropriate tuple in SG> table "shift" for this tuple (matching day, shift-of-the-day and workplace) SG> and denormalizes fields. SG> 2. INSERT INTO shift. SG> An AFTER INSERT/UPDATE/DELETE trigger updates rows in table barcode, forcing SG> the abovementioned check for shift. SG> The second one is a long process, taking about 20 sec to finish. Imagine the SG> following scenario: SG> x:xx:00 INSERT INTO shift. SG> Transaction "S" begins. SG> It updates several rows, but not the not-yet-inserted row. SG> x:xx:10 INSERT INTO barcode (... appropriate for above-inserted shift ...) SG> Transaction "B" begins. SG> It checks but does not find the corresponding shift. SG> x:xx:11 Transaction "B" ends. SG> x:xx:20 Transaction "S" ends. SG> In such scenarios, sometimes we get "Deadlock detected." That's OK since the SG> transactions actually cross each other's way. SG> But not always. In about 100 inserts, now we have the first case that did SG> not show any trace of that something went wrong. SG> 1. Is there a way to detect such "crossing" transactions? SG> 2. Is there a thorough article on deadlocks, how and when do they happen? SG> 3. Maybe a section of the postgresql doc clarifying when do tuples get locked? A helyzet elkerulesere talan tudok egy modszert. A barcode tablaba insertalast szervezd tranzakcioba, es access exclusive moddal lockold az elejen(mindenkeppen meg az insert elott) a shift tablat. Igy mig "S" tranzakcio folyamatban van, addig a "B" nem indulhat el az exclusiv lock igenye miatt, es mig a "B" var a sorara, addig ujabb "S"-t sem enged elindulni. Igy elkerulheted az egymast keresztbe vero tranzakciokat, ami a deadlockhoz szokott vezetni. DAQ ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [SQL] Number of rows in a cursor ?
You cannot count the number of rows in a cursor, unfortunately. I recently ran in to this problem. As far as I am aware, the only way to count them is to either iterate through them, or if you are only expecting one or two, perform multiple FETCHES and test if the record set returned is empty. http://archives.postgresql.org/pgsql-sql/2005-08/msg00208.php OPEN cur_overlap FOR EXECUTE 'SELECT *, '; FETCH cur_overlap INTO row_one; FETCH cur_overlap INTO row_two; IF (row_two.id IS NULL) THEN King regards, Neil. This message is for the designated recipient only and may contain privileged, proprietary, or otherwise private information. If you have received it in error, please notify the sender immediately and delete the original. Any other use of the email by you is prohibited. ---(end of broadcast)--- TIP 6: explain analyze is your friend
Re: [SQL] Number of rows in a cursor ?
Thomas Borg Salling wrote: Bo Lorentsen wrote: Is it possible to get the total number of rows found in a cursor, or must I make a count(*) and then a select ? Perhaps: GET DIAGNOSTICS rc = ROW_COUNT; Ok, and when I use the C interface the "DECLARE .." function will return the row count ? Can I use PQntuples( res ) after the "DECLARE CURSOR" statement (if so, it don't work for me :-)) ? /BL ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
Re: [SQL] Number of rows in a cursor ?
[EMAIL PROTECTED] wrote: You cannot count the number of rows in a cursor, unfortunately. I recently ran in to this problem. How sad, then I have to repeat the query, first for counting and last for data fetch :-( /BL ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
[SQL] SQLException - SET AUTOCOMMIT TO OFF is no longer supported
I have created datasource but getting this error on JBOSS startup. Using: PostgreSQL 8.0 JBOSS: JBOSS-3.2.6 16:09:37,093 WARN [TransactionImpl] XAException: tx=TransactionImpl:XidImpl [FormatId=257, GlobalId=dinesh//1, BranchQual=] errorCode=XA_UNKNOWN(0) org.jboss.resource.connectionmanager.JBossLocalXAException: Error trying to start local tx: ; - nested throwable: (org.jboss.resource.JBossResourceException: SQLException; - nested throwable: (java.sql.SQLException: ERROR: SET AUTOCOMMIT TO OFF is no longer supported )) at org.jboss.resource.connectionmanager.TxConnectionManager$LocalXAResource.start(TxConnectionManager.java:654) at org.jboss.tm.TransactionImpl.startResource(TransactionImpl.java:1196) at org.jboss.tm.TransactionImpl.enlistResource(TransactionImpl.java:649) Thanks Dinesh Pandey
Re: [SQL] SQLException - SET AUTOCOMMIT TO OFF is no longer supported
After using correct version of JDBC driver I am able to start JBOSS server. Thanks Dinesh Pandey I have created datasource but getting this error on JBOSS startup. Using: PostgreSQL 8.0 JBOSS: JBOSS-3.2.6 16:09:37,093 WARN [TransactionImpl] XAException: tx=TransactionImpl:XidImpl [FormatId=257, GlobalId=dinesh//1, BranchQual=] errorCode=XA_UNKNOWN(0) org.jboss.resource.connectionmanager.JBossLocalXAException: Error trying to start local tx: ; - nested throwable: (org.jboss.resource.JBossResourceException: SQLException; - nested throwable: (java.sql.SQLException: ERROR: SET AUTOCOMMIT TO OFF is no longer supported )) at org.jboss.resource.connectionmanager.TxConnectionManager$LocalXAResource.start(TxConnectionManager.java:654) at org.jboss.tm.TransactionImpl.startResource(TransactionImpl.java:1196) at org.jboss.tm.TransactionImpl.enlistResource(TransactionImpl.java:649) Thanks Dinesh Pandey
Re: [SQL] Number of rows in a cursor ?
[EMAIL PROTECTED] wrote: You cannot count the number of rows in a cursor, unfortunately. I recently ran in to this problem. How sad, then I have to repeat the query, first for counting and last for data fetch :-( /BL If you need a count, why not just execute one of the methods to get a count. i.e.e select count(id) ... ---(end of broadcast)--- TIP 5: don't forget to increase your free space map settings
Re: [SQL] SQLException - SET AUTOCOMMIT TO OFF is no longer supported
16:09:37,093 WARN [TransactionImpl] XAException: tx=TransactionImpl:XidImpl [FormatId=257, GlobalId=dinesh//1, BranchQual=] errorCode=XA_UNKNOWN(0) org.jboss.resource.connectionmanager.JBossLocalXAException: Error trying to start local tx: ; - nested throwable: (org.jboss.resource.JBossResourceException: SQLException; - nested throwable: (java.sql.SQLException: ERROR: SET AUTOCOMMIT TO OFF is no longer supported )) at org.jboss.resource.connectionmanager.TxConnectionManager$LocalXAResource.start(TxConnectionManager.java:654) at org.jboss.tm.TransactionImpl.startResource(TransactionImpl.java:1196) at org.jboss.tm.TransactionImpl.enlistResource(TransactionImpl.java:649) ThanksDinesh Pandey
Re: [SQL] SQLException - SET AUTOCOMMIT TO OFF is no longer supported
I have created datasource but getting this error on JBOSS startup. Using: PostgreSQL 8.0 JBOSS: JBOSS-3.2.6 16:09:37,093 WARN [TransactionImpl] XAException: tx=TransactionImpl:XidImpl [FormatId=257, GlobalId=dinesh//1, BranchQual=] errorCode=XA_UNKNOWN(0) org.jboss.resource.connectionmanager.JBossLocalXAException: Error trying to start local tx: ; - nested throwable: (org.jboss.resource.JBossResourceException: SQLException; - nested throwable: (java.sql.SQLException: ERROR: SET AUTOCOMMIT TO OFF is no longer supported )) at org.jboss.resource.connectionmanager.TxConnectionManager$LocalXAResource.start(TxConnectionManager.java:654) at org.jboss.tm.TransactionImpl.startResource(TransactionImpl.java:1196) at org.jboss.tm.TransactionImpl.enlistResource(TransactionImpl.java:649) ThanksDinesh Pandey I think you need to get a more up to date version of your JDBC Driver
Re: [SQL] Number of rows in a cursor ?
On Aug 24, 2005, at 6:31 AM, Bo Lorentsen wrote: How sad, then I have to repeat the query, first for counting and last for data fetch :-( No, you can use the MOVE command and read how many rows you moved with something like MOVE LAST IN mycursor; http://www.postgresql.org/docs/8.0/interactive/sql-move.html John DeSoi, Ph.D. http://pgedit.com/ Power Tools for PostgreSQL ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [SQL] SQLException - SET AUTOCOMMIT TO OFF is no longer supported
I am getting ready to start using jboss with postgres (newer to jboss then postgres). Is there a mailing list for java postgres support? Can you post the connection elements for JBOSS or is that something documented in the JDBC driver? Joel Fradkin Wazagua, Inc. 2520 Trailmate Dr Sarasota, Florida 34243 Tel. 941-753-7111 ext 305 [EMAIL PROTECTED] www.wazagua.com Powered by Wazagua Providing you with the latest Web-based technology & advanced tools. © 2004. WAZAGUA, Inc. All rights reserved. WAZAGUA, Inc This email message is for the use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and delete and destroy all copies of the original message, including attachments. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dinesh Pandey Sent: Wednesday, August 24, 2005 7:22 AM To: 'PostgreSQL' Subject: Re: [SQL] SQLException - SET AUTOCOMMIT TO OFF is no longer supported After using correct version of JDBC driver I am able to start JBOSS server. Thanks Dinesh Pandey I have created datasource but getting this error on JBOSS startup. Using: PostgreSQL 8.0 JBOSS: JBOSS-3.2.6 16:09:37,093 WARN [TransactionImpl] XAException: tx=TransactionImpl:XidImpl [FormatId=257, GlobalId=dinesh//1, BranchQual=] errorCode=XA_UNKNOWN(0) org.jboss.resource.connectionmanager.JBossLocalXAException: Error trying to start local tx: ; - nested throwable: (org.jboss.resource.JBossResourceException: SQLException; - nested throwable: (java.sql.SQLException: ERROR: SET AUTOCOMMIT TO OFF is no longer supported )) at org.jboss.resource.connectionmanager.TxConnectionManager$LocalXAResource.start(TxConnectionManager.java:654) at org.jboss.tm.TransactionImpl.startResource(TransactionImpl.java:1196) at org.jboss.tm.TransactionImpl.enlistResource(TransactionImpl.java:649) Thanks Dinesh Pandey
Re: [SQL] Number of rows in a cursor ?
Russell Simpkins wrote: If you need a count, why not just execute one of the methods to get a count. i.e.e select count(id) ... The reason why i don't just make a count and then a selection of data is performance. /BL ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [SQL] Number of rows in a cursor ?
On Wed, Aug 24, 2005 at 02:50:07PM +0200, Bo Lorentsen wrote: > Russell Simpkins wrote: > >If you need a count, why not just execute one of the methods to get a > >count. i.e.e select count(id) ... > > The reason why i don't just make a count and then a selection of data > is performance. ...which is the same reason a cursor doesn't know how many rows it will fetch until you fetch them all (or MOVE to the end of the cursor, which fetches the rows internally). -- Michael Fuhr ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
[SQL] How to join several selects
Hello, I have a 'big' problem: I have the following table users(name, start_time, end_time), a new row is set whenever a user logs into a server. I want to know how many users have logged in EVERYDAY between 2 different dates. The only idea that I have is making several select (one for each day): SELECT COUNT(name) FROM users WHERE start_time between "startDate" and "startDate+1" SELECT COUNT(name) FROM users WHERE start_time between "startDate+1" and "startDate+2" ... I would like to know if its possible to make it in 1 sql statement or just which is the best efficient way to solve it. By the way, I use Postgres 7.4. Thanks! -- Josep Sanmarti Analista de Projectes Grup OpenWired, S.L. Caballero, 87 - 08029 - Barcelona (Spain) Tel (+34) 93/410 75 70 - Fax (+34) 93/419 45 91 ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
Re: [SQL] How to join several selects
On 8/24/05 9:46 AM, "Josep Sanmartí" <[EMAIL PROTECTED]> wrote: > Hello, > I have a 'big' problem: > I have the following table users(name, start_time, end_time), a new row > is set whenever a user logs into a server. I want to know how many > users have logged in EVERYDAY between 2 different dates. The only idea > that I have is making several select (one for each day): > SELECT COUNT(name) FROM users WHERE start_time between "startDate" > and "startDate+1" > SELECT COUNT(name) FROM users WHERE start_time between "startDate+1" > and "startDate+2" > ... > I would like to know if its possible to make it in 1 sql statement or > just which is the best efficient way to solve it. > By the way, I use Postgres 7.4. See: http://www.postgresql.org/docs/8.0/interactive/sql-select.html#SQL-UNION like: SELECT COUNT(name) FROM users WHERE start_time between "startDate" and "startDate+1" union SELECT COUNT(name) FROM users WHERE start_time between "startDate+1" and "startDate+2" Sean ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [SQL] How to join several selects
On Wed, 2005-08-24 at 15:46 +0200, Josep Sanmartí wrote: > Hello, > I have a 'big' problem: > I have the following table users(name, start_time, end_time), a new row > is set whenever a user logs into a server. I want to know how many > users have logged in EVERYDAY between 2 different dates. The only idea > that I have is making several select (one for each day): > SELECT COUNT(name) FROM users WHERE start_time between "startDate" > and "startDate+1" > SELECT COUNT(name) FROM users WHERE start_time between "startDate+1" > and "startDate+2" You have columns named "startDate+2" or are you adding 2 days to a column named "startDate"? -- ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [SQL] How to join several selects
On Aug 24, 2005, at 11:03 PM, Sean Davis wrote: On 8/24/05 9:46 AM, "Josep Sanmartí" <[EMAIL PROTECTED]> wrote: Hello, I have a 'big' problem: I have the following table users(name, start_time, end_time), a new row is set whenever a user logs into a server. I want to know how many users have logged in EVERYDAY between 2 different dates. The only idea that I have is making several select (one for each day): SELECT COUNT(name) FROM users WHERE start_time between "startDate" and "startDate+1" SELECT COUNT(name) FROM users WHERE start_time between "startDate +1" and "startDate+2" ... I would like to know if its possible to make it in 1 sql statement or just which is the best efficient way to solve it. By the way, I use Postgres 7.4. See: http://www.postgresql.org/docs/8.0/interactive/sql-select.html#SQL- UNION like: SELECT COUNT(name) FROM users WHERE start_time between "startDate" and "startDate+1" union SELECT COUNT(name) FROM users WHERE start_time between "startDate+1" and "startDate+2" I'm guessing he wants something more like this, so he knows which period is which: SELECT count_1, count_2 FROM ( SELECT COUNT(name) AS count_1 FROM users WHERE start_time BETWEEN startDate AND startDate + 1 ) as period_1 CROSS JOIN ( SELECT COUNT(name) AS count_2 FROM users WHERE start_time BETWEEN startDate + 1 AND startDate + 2 ) as period_2 Though, you could do the same thing using UNION like this: SELECT 'period_1'::text as period, COUNT(name) AS num_of_users FROM users WHERE start_time BETWEEN startDate AND startDate + 1 UNION SELECT 'period_2'::text as period, COUNT(name) AS num_of_users FROM users WHERE start_time BETWEEN startDate + 1 AND startDate + 2 And of course, using EXPLAIN ANALYZE will help decide which is more performant. Michael Glaesemann grzm myrealbox com ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [SQL] Number of rows in a cursor ?
Michael Fuhr wrote: ...which is the same reason a cursor doesn't know how many rows it will fetch until you fetch them all (or MOVE to the end of the cursor, which fetches the rows internally). So, Postgresql is not hidding something for me, it just, like me, don't know ? /BL ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
Re: [SQL] How to join several selects
Josep Sanmartí wrote:
Hello,
I have a 'big' problem:
I have the following table users(name, start_time, end_time), a new row
is set whenever a user logs into a server. I want to know how many
users have logged in EVERYDAY between 2 different dates. The only idea
that I have is making several select (one for each day):
SELECT COUNT(name) FROM users WHERE start_time between "startDate"
and "startDate+1"
SELECT COUNT(name) FROM users WHERE start_time between "startDate+1"
and "startDate+2"
...
I would like to know if its possible to make it in 1 sql statement or
just which is the best efficient way to solve it.
By the way, I use Postgres 7.4.
Thanks!
SELECT
date_trunc('day', start_time) as day, count(name)
FROM
users
WHERE
start_time between "startDate" AND "endDate"
GROUP BY
day;
---(end of broadcast)---
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Re: [SQL] Number of rows in a cursor ?
On Wed, Aug 24, 2005 at 04:29:00PM +0200, Bo Lorentsen wrote: > Michael Fuhr wrote: > >...which is the same reason a cursor doesn't know how many rows it will > >fetch until you fetch them all (or MOVE to the end of the cursor, > >which fetches the rows internally). > > So, Postgresql is not hidding something for me, it just, like me, don't > know ? Right -- when you open a cursor PostgreSQL doesn't know how many rows it will return. PostgreSQL selects a query plan based on an *estimate* of how many rows the query will return, but until you fetch all the rows you can't know for sure how many rows there will be. -- Michael Fuhr ---(end of broadcast)--- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
Re: [SQL] how to do a select * and decrypt a column at the same
On Tue, 2005-08-16 at 14:53, The One wrote: > Hello, > > I have a table with one encrypted column. > How can I do a select statement such that it will select all columns > from the table and at the same time will decrypt it too? A view should be able to do that... ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
[SQL] Can EXCEPT Be Used for To Solve This Problem?
Given the following data in a table named 'foo' : id update_time description 22005-08-24 00:10:00 transaction1 22005-08-24 00:22:00 transaction2 22005-08-24 00:34:00 transaction3 22005-08-24 00:58:00 transaction4 I want to select 2nd oldest transaction from foo (transaction 3). The solution below works, but I think there may be a better way. Does anyone else have a better idea? select * from foo f1 join (select id, update_time from foo except select id, max(update_time) as update_time from foo group by id) f2 using (id, update_time) order by 1, 2 desc limit 1; ---(end of broadcast)--- TIP 2: Don't 'kill -9' the postmaster
Re: [SQL] Can EXCEPT Be Used for To Solve This Problem?
On Wed, Aug 24, 2005 at 04:47:16PM -0400, Lane Van Ingen wrote: > Given the following data in a table named 'foo' : > id update_time description > 22005-08-24 00:10:00 transaction1 > 22005-08-24 00:22:00 transaction2 > 22005-08-24 00:34:00 transaction3 > 22005-08-24 00:58:00 transaction4 > > I want to select 2nd oldest transaction from foo (transaction 3). The > solution below > works, but I think there may be a better way. Does anyone else have a better > idea? Do you want the 2nd oldest transaction from the entire table? If so then the following should work: SELECT * FROM foo ORDER BY update_time OFFSET 1 LIMIT 1; If that's not what you're after then please elaborate. -- Michael Fuhr ---(end of broadcast)--- TIP 6: explain analyze is your friend
Re: [SQL] Can EXCEPT Be Used for To Solve This Problem?
"Lane Van Ingen" <[EMAIL PROTECTED]> writes: > I want to select 2nd oldest transaction from foo (transaction 3). Can't you just do select * from foo order by update_time desc offset 1 limit 1 regards, tom lane ---(end of broadcast)--- TIP 3: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faq
Re: [SQL] Can EXCEPT Be Used for To Solve This Problem?
On Wed, Aug 24, 2005 at 05:34:49PM -0600, Michael Fuhr wrote: > On Wed, Aug 24, 2005 at 04:47:16PM -0400, Lane Van Ingen wrote: > > Given the following data in a table named 'foo' : > > id update_time description > > 22005-08-24 00:10:00 transaction1 > > 22005-08-24 00:22:00 transaction2 > > 22005-08-24 00:34:00 transaction3 > > 22005-08-24 00:58:00 transaction4 > > > > I want to select 2nd oldest transaction from foo (transaction 3). The I just noticed that transaction3 isn't the 2nd oldest, it's the 3rd oldest and the 2nd newest. What are you really trying to do? > > solution below > > works, but I think there may be a better way. Does anyone else have a better > > idea? > > Do you want the 2nd oldest transaction from the entire table? If > so then the following should work: > > SELECT * > FROM foo > ORDER BY update_time > OFFSET 1 > LIMIT 1; Flaw: this query assumes that the 2nd record in the ordered result set is the 2nd oldest transaction, which isn't necessarily true. If the update_time values aren't unique, then the 2nd record could have the oldest time and not the 2nd oldest time. Is that why you were using EXCEPT? To exclude all instances of the oldest time? -- Michael Fuhr ---(end of broadcast)--- TIP 4: Have you searched our list archives? http://archives.postgresql.org
Re: [SQL] Number of rows in a cursor ?
Michael Fuhr wrote: Right -- when you open a cursor PostgreSQL doesn't know how many rows it will return. PostgreSQL selects a query plan based on an *estimate* of how many rows the query will return, but until you fetch all the rows you can't know for sure how many rows there will be. So if i make a but data set as result of a cursor I only "pay" for the rows I actually fetch ? /BL ---(end of broadcast)--- TIP 1: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
