Re: [sqlalchemy] event overhead question
On Thursday, October 11, 2018 at 11:26:57 PM UTC-4, Mike Bayer wrote: > > > the overhead of using @event.listens on that setter will be almost > undetectable.of course it also depends on what you're doing once > youre in the event handler. > > Great! Thanks. I'm just setting a bunch of attributes on the object to None. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
Re: [sqlalchemy] event overhead question
On Thu, Oct 11, 2018 at 11:01 PM Jonathan Vanasco wrote: > > > > On Thursday, October 11, 2018 at 7:29:32 PM UTC-4, Mike Bayer wrote: >> >> >> overhead is fairly minimal, but also, a "set" is something you're >> doing at very specific times, so, how much is this "set" being called >> typically? > > > The app is a read-heavy CMS. This "set" happens on the Article's body via > create or edit. These two write operations are maybe 1/1000th the volume of > total writes, and writes are maybe 1 per 100k reads. > > Using the event would be a small convenience in some ways and a good a backup > plan, but the system can easily use a custom setter for the object. the overhead of using @event.listens on that setter will be almost undetectable.of course it also depends on what you're doing once youre in the event handler. > > -- > SQLAlchemy - > The Python SQL Toolkit and Object Relational Mapper > > http://www.sqlalchemy.org/ > > To post example code, please provide an MCVE: Minimal, Complete, and > Verifiable Example. See http://stackoverflow.com/help/mcve for a full > description. > --- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy+unsubscr...@googlegroups.com. > To post to this group, send email to sqlalchemy@googlegroups.com. > Visit this group at https://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/d/optout. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
Re: [sqlalchemy] event overhead question
On Thursday, October 11, 2018 at 7:29:32 PM UTC-4, Mike Bayer wrote: > > > overhead is fairly minimal, but also, a "set" is something you're > doing at very specific times, so, how much is this "set" being called > typically? > The app is a read-heavy CMS. This "set" happens on the Article's body via create or edit. These two write operations are maybe 1/1000th the volume of total writes, and writes are maybe 1 per 100k reads. Using the event would be a small convenience in some ways and a good a backup plan, but the system can easily use a custom setter for the object. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
Re: [sqlalchemy] event overhead question
On Thu, Oct 11, 2018 at 7:27 PM Jonathan Vanasco wrote: > > I try to stay away from Events in production. > > I now need to catch modifications of a particular column in order to expire > some data cached onto the object. > > Is there a measurable overhead for catching a single column? e.g. > > @event.listens_for(ObjectClass.column, 'set') > > The alternative is to use a setter function - which I am fine with. > > This is in an app that needs to be a bit more performance oriented, so I > figured I would ask before doing a benchmark. overhead is fairly minimal, but also, a "set" is something you're doing at very specific times, so, how much is this "set" being called typically? > > -- > SQLAlchemy - > The Python SQL Toolkit and Object Relational Mapper > > http://www.sqlalchemy.org/ > > To post example code, please provide an MCVE: Minimal, Complete, and > Verifiable Example. See http://stackoverflow.com/help/mcve for a full > description. > --- > You received this message because you are subscribed to the Google Groups > "sqlalchemy" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to sqlalchemy+unsubscr...@googlegroups.com. > To post to this group, send email to sqlalchemy@googlegroups.com. > Visit this group at https://groups.google.com/group/sqlalchemy. > For more options, visit https://groups.google.com/d/optout. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
[sqlalchemy] event overhead question
I try to stay away from Events in production. I now need to catch modifications of a particular column in order to expire some data cached onto the object. Is there a measurable overhead for catching a single column? e.g. @event.listens_for(ObjectClass.column, 'set') The alternative is to use a setter function - which I am fine with. This is in an app that needs to be a bit more performance oriented, so I figured I would ask before doing a benchmark. -- SQLAlchemy - The Python SQL Toolkit and Object Relational Mapper http://www.sqlalchemy.org/ To post example code, please provide an MCVE: Minimal, Complete, and Verifiable Example. See http://stackoverflow.com/help/mcve for a full description. --- You received this message because you are subscribed to the Google Groups "sqlalchemy" group. To unsubscribe from this group and stop receiving emails from it, send an email to sqlalchemy+unsubscr...@googlegroups.com. To post to this group, send email to sqlalchemy@googlegroups.com. Visit this group at https://groups.google.com/group/sqlalchemy. For more options, visit https://groups.google.com/d/optout.
