db:drop error not being caught

Von: Lizzi, Vincent via BaseX-Talk <basex-talk at mailman.uni-konstanz.de> Gesendet: Donnerstag, September 25, 2025 9:15:45 PM An: Christian Grün via BaseX-Talk <basex-talk at mailman.uni-konstanz.de> Betreff: [basex-talk] db:drop error not being caught Hi all, I have a query that is intended to delete outdated databases. This has been working but I recently found that if a database is locked the process stops with an error such as: [db:lock] Database 'name' cannot be updated, it is opened by another process. As a result, the process is stopped by any database being in a locked state. I would have thought that the try / catch around db:drop would catch the error and allow the process to skip over any locked databases. declare variable $age external := 'PT1M'; (: age 1 minute for testing :) let $cutoff := current-dateTime() - xs:dayTimeDuration($age) let $databases := db:list-details()[xs:dateTime(@modified-date) lt $cutoff] return ( admin:write-log('cleanup delete items older than ' || $cutoff), for $db in $databases return ( admin:write-log('cleanup deleting database ' || $db), try { db:drop($db) } catch * { admin:write-log('cleanup error deleting ' || $db || ': ' || $err:description, 'ERROR') } ) ) I tried replacing catch * with catch db:open to catch the specific error, but that hasn't helped. Why is the error not caught, and is there a better way to write this query to avoid this problem? Thanks, Vincent Vincent M. Lizzi Head of Information Standards | Taylor & Francis Group E-Mail: vincent.lizzi at taylorandfrancis.com<mailto:vincent.lizzi at taylorandfrancis.com> Web: www.tandfonline.com<http://www.tandfonline.com/> Time zone: US Eastern Taylor & Francis is a trading name of Informa UK Limited, registered in England under no. 1072954 "Everything should be made as simple as possible, but not simpler." [cid:8d80b1b7-f927-4cb7-a971-709e53dbf8b7]<https://outlook.office.com/bookwithme/user/aa80d42cbb5b46dba06a5ad241d7665b at taylorandfrancis.com?anonymous&ep=owaSlotsEmailSignature> Book time to meet with me<https://outlook.office.com/bookwithme/user/aa80d42cbb5b46dba06a5ad241d7665b at taylorandfrancis.com?anonymous&ep=owaSlotsEmailSignature>

From: Christian Grün <cg at basex.org> Sent: Saturday, September 27, 2025 3:05 AM To: Lizzi, Vincent <Vincent.Lizzi at taylorandfrancis.com>; Christian Grün via BaseX-Talk <basex-talk at mailman.uni-konstanz.de> Subject: Re: db:drop error not being caught Hi Vincent, Database updates are not immediately processed, but added to the so-called PUL (pending update list) [1] and executed at the very end of the query. When the updates are executed. This means that try/catch won’t have any effect, as the mere addition of the operation to the PUL does not raise any errors. The interesting question is why the error is raised at all. Do you have multiple independent instances of BaseX that access the same databases? If not, can you imagine an example that allows us to reproduce the behavior? Best, Christian [1] https://docs.basex.org/main/Updates#pending_update_list<https://docs.basex.org/main/Updates#pending_update_list> Von: Lizzi, Vincent via BaseX-Talk <basex-talk at mailman.uni-konstanz.de> Gesendet: Donnerstag, September 25, 2025 9:15:45 PM An: Christian Grün via BaseX-Talk <basex-talk at mailman.uni-konstanz.de> Betreff: [basex-talk] db:drop error not being caught Hi all, I have a query that is intended to delete outdated databases. This has been working but I recently found that if a database is locked the process stops with an error such as: [db:lock] Database 'name' cannot be updated, it is opened by another process. As a result, the process is stopped by any database being in a locked state. I would have thought that the try / catch around db:drop would catch the error and allow the process to skip over any locked databases. declare variable $age external := 'PT1M'; (: age 1 minute for testing :) let $cutoff := current-dateTime() - xs:dayTimeDuration($age) let $databases := db:list-details()[xs:dateTime(@modified-date) lt $cutoff] return ( admin:write-log('cleanup delete items older than ' || $cutoff), for $db in $databases return ( admin:write-log('cleanup deleting database ' || $db), try { db:drop($db) } catch * { admin:write-log('cleanup error deleting ' || $db || ': ' || $err:description, 'ERROR') } ) ) I tried replacing catch * with catch db:open to catch the specific error, but that hasn't helped. Why is the error not caught, and is there a better way to write this query to avoid this problem? Thanks, Vincent Vincent M. Lizzi Head of Information Standards | Taylor & Francis Group E-Mail: vincent.lizzi at taylorandfrancis.com<mailto:vincent.lizzi at taylorandfrancis.com> Web: www.tandfonline.com<http://www.tandfonline.com/> Time zone: US Eastern Taylor & Francis is a trading name of Informa UK Limited, registered in England under no. 1072954 "Everything should be made as simple as possible, but not simpler." [cid:8d80b1b7-f927-4cb7-a971-709e53dbf8b7]<https://outlook.office.com/bookwithme/user/aa80d42cbb5b46dba06a5ad241d7665b at taylorandfrancis.com?anonymous&ep=owaSlotsEmailSignature> Book time to meet with me<https://outlook.office.com/bookwithme/user/aa80d42cbb5b46dba06a5ad241d7665b at taylorandfrancis.com?anonymous&ep=owaSlotsEmailSignature> Information Classification: General

> I encountered this specific error using BaseX GUI by running this script while a database was open.

> If db:list() is not working, is there any way to identify which databases might be corrupt, locked, or somehow causing a problem?

From: Christian Grün <cg at basex.org> Sent: Monday, September 29, 2025 4:44:42 AM To: Lizzi, Vincent <Vincent.Lizzi at taylorandfrancis.com>; Christian Grün via BaseX-Talk <basex-talk at mailman.uni-konstanz.de> Subject: AW: db:drop error not being caught Hi Vincent, > I encountered this specific error using BaseX GUI by running this script while a database was open. I see: Mixing the GUI and other independent BaseX instances may indeed unexpected errors. > If db:list() is not working, is there any way to identify which databases might be corrupt, locked, or somehow causing a problem? In principle, db:list() (without arguments) is nothing else than a file:list() operation for the database directory. You should be able to simulate it with: for $db in file:children(db:option('dbpath')) where file:is-dir($db) return file:name($db) Do you remember what happened when you tried to use db:list? Best, Christian