Re: [openstack-dev] savann-ci, Re: [savanna] Alembic migrations and absence of DROP column in sqlite
Agreed, let's move on to the MySQL for savanna-ci to run integration tests against production-like DB. On Wed, Feb 5, 2014 at 1:54 AM, Andrew Lazarev alaza...@mirantis.comwrote: Since sqlite is not in the list of databases that would be used in production, CI should use other DB for testing. Andrew. On Tue, Feb 4, 2014 at 1:13 PM, Alexander Ignatov aigna...@mirantis.comwrote: Indeed. We should create a bug around that and move our savanna-ci to mysql. Regards, Alexander Ignatov On 05 Feb 2014, at 01:01, Trevor McKay tmc...@redhat.com wrote: This brings up an interesting problem: In https://review.openstack.org/#/c/70420/ I've added a migration that uses a drop column for an upgrade. But savann-ci is apparently using a sqlite database to run. So it can't possibly pass. What do we do here? Shift savanna-ci tests to non sqlite? Trevor On Sat, 2014-02-01 at 18:17 +0200, Roman Podoliaka wrote: Hi all, My two cents. 2) Extend alembic so that op.drop_column() does the right thing We could, but should we? The only reason alembic doesn't support these operations for SQLite yet is that SQLite lacks proper support of ALTER statement. For sqlalchemy-migrate we've been providing a work-around in the form of recreating of a table and copying of all existing rows (which is a hack, really). But to be able to recreate a table, we first must have its definition. And we've been relying on SQLAlchemy schema reflection facilities for that. Unfortunately, this approach has a few drawbacks: 1) SQLAlchemy versions prior to 0.8.4 don't support reflection of unique constraints, which means the recreated table won't have them; 2) special care must be taken in 'edge' cases (e.g. when you want to drop a BOOLEAN column, you must also drop the corresponding CHECK (col in (0, 1)) constraint manually, or SQLite will raise an error when the table is recreated without the column being dropped) 3) special care must be taken for 'custom' type columns (it's got better with SQLAlchemy 0.8.x, but e.g. in 0.7.x we had to override definitions of reflected BIGINT columns manually for each column.drop() call) 4) schema reflection can't be performed when alembic migrations are run in 'offline' mode (without connecting to a DB) ... (probably something else I've forgotten) So it's totally doable, but, IMO, there is no real benefit in supporting running of schema migrations for SQLite. ...attempts to drop schema generation based on models in favor of migrations As long as we have a test that checks that the DB schema obtained by running of migration scripts is equal to the one obtained by calling metadata.create_all(), it's perfectly OK to use model definitions to generate the initial DB schema for running of unit-tests as well as for new installations of OpenStack (and this is actually faster than running of migration scripts). ... and if we have strong objections against doing metadata.create_all(), we can always use migration scripts for both new installations and upgrades for all DB backends, except SQLite. Thanks, Roman On Sat, Feb 1, 2014 at 12:09 PM, Eugene Nikanorov enikano...@mirantis.com wrote: Boris, Sorry for the offtopic. Is switching to model-based schema generation is something decided? I see the opposite: attempts to drop schema generation based on models in favor of migrations. Can you point to some discussion threads? Thanks, Eugene. On Sat, Feb 1, 2014 at 2:19 AM, Boris Pavlovic bpavlo...@mirantis.com wrote: Jay, Yep we shouldn't use migrations for sqlite at all. The major issue that we have now is that we are not able to ensure that DB schema created by migration models are same (actually they are not same). So before dropping support of migrations for sqlite switching to model based created schema we should add tests that will check that model migrations are synced. (we are working on this) Best regards, Boris Pavlovic On Fri, Jan 31, 2014 at 7:31 PM, Andrew Lazarev alaza...@mirantis.com wrote: Trevor, Such check could be useful on alembic side too. Good opportunity for contribution. Andrew. On Fri, Jan 31, 2014 at 6:12 AM, Trevor McKay tmc...@redhat.com wrote: Okay, I can accept that migrations shouldn't be supported on sqlite. However, if that's the case then we need to fix up savanna-db-manage so that it checks the db connection info and throws a polite error to the user for attempted migrations on unsupported platforms. For example: Database migrations are not supported for sqlite Because, as a developer, when I see a sql error trace as the result of an operation I assume it's broken :) Best, Trevor On Thu, 2014-01-30 at 15:04 -0500, Jay Pipes wrote: On Thu, 2014-01-30 at 14:51 -0500, Trevor McKay wrote: I was playing with
Re: [openstack-dev] savann-ci, Re: [savanna] Alembic migrations and absence of DROP column in sqlite
I'm currently working on moving on the MySQL for savanna-ci On Wed, Feb 5, 2014 at 3:53 PM, Sergey Lukjanov slukja...@mirantis.comwrote: Agreed, let's move on to the MySQL for savanna-ci to run integration tests against production-like DB. On Wed, Feb 5, 2014 at 1:54 AM, Andrew Lazarev alaza...@mirantis.comwrote: Since sqlite is not in the list of databases that would be used in production, CI should use other DB for testing. Andrew. On Tue, Feb 4, 2014 at 1:13 PM, Alexander Ignatov aigna...@mirantis.comwrote: Indeed. We should create a bug around that and move our savanna-ci to mysql. Regards, Alexander Ignatov On 05 Feb 2014, at 01:01, Trevor McKay tmc...@redhat.com wrote: This brings up an interesting problem: In https://review.openstack.org/#/c/70420/ I've added a migration that uses a drop column for an upgrade. But savann-ci is apparently using a sqlite database to run. So it can't possibly pass. What do we do here? Shift savanna-ci tests to non sqlite? Trevor On Sat, 2014-02-01 at 18:17 +0200, Roman Podoliaka wrote: Hi all, My two cents. 2) Extend alembic so that op.drop_column() does the right thing We could, but should we? The only reason alembic doesn't support these operations for SQLite yet is that SQLite lacks proper support of ALTER statement. For sqlalchemy-migrate we've been providing a work-around in the form of recreating of a table and copying of all existing rows (which is a hack, really). But to be able to recreate a table, we first must have its definition. And we've been relying on SQLAlchemy schema reflection facilities for that. Unfortunately, this approach has a few drawbacks: 1) SQLAlchemy versions prior to 0.8.4 don't support reflection of unique constraints, which means the recreated table won't have them; 2) special care must be taken in 'edge' cases (e.g. when you want to drop a BOOLEAN column, you must also drop the corresponding CHECK (col in (0, 1)) constraint manually, or SQLite will raise an error when the table is recreated without the column being dropped) 3) special care must be taken for 'custom' type columns (it's got better with SQLAlchemy 0.8.x, but e.g. in 0.7.x we had to override definitions of reflected BIGINT columns manually for each column.drop() call) 4) schema reflection can't be performed when alembic migrations are run in 'offline' mode (without connecting to a DB) ... (probably something else I've forgotten) So it's totally doable, but, IMO, there is no real benefit in supporting running of schema migrations for SQLite. ...attempts to drop schema generation based on models in favor of migrations As long as we have a test that checks that the DB schema obtained by running of migration scripts is equal to the one obtained by calling metadata.create_all(), it's perfectly OK to use model definitions to generate the initial DB schema for running of unit-tests as well as for new installations of OpenStack (and this is actually faster than running of migration scripts). ... and if we have strong objections against doing metadata.create_all(), we can always use migration scripts for both new installations and upgrades for all DB backends, except SQLite. Thanks, Roman On Sat, Feb 1, 2014 at 12:09 PM, Eugene Nikanorov enikano...@mirantis.com wrote: Boris, Sorry for the offtopic. Is switching to model-based schema generation is something decided? I see the opposite: attempts to drop schema generation based on models in favor of migrations. Can you point to some discussion threads? Thanks, Eugene. On Sat, Feb 1, 2014 at 2:19 AM, Boris Pavlovic bpavlo...@mirantis.com wrote: Jay, Yep we shouldn't use migrations for sqlite at all. The major issue that we have now is that we are not able to ensure that DB schema created by migration models are same (actually they are not same). So before dropping support of migrations for sqlite switching to model based created schema we should add tests that will check that model migrations are synced. (we are working on this) Best regards, Boris Pavlovic On Fri, Jan 31, 2014 at 7:31 PM, Andrew Lazarev alaza...@mirantis.com wrote: Trevor, Such check could be useful on alembic side too. Good opportunity for contribution. Andrew. On Fri, Jan 31, 2014 at 6:12 AM, Trevor McKay tmc...@redhat.com wrote: Okay, I can accept that migrations shouldn't be supported on sqlite. However, if that's the case then we need to fix up savanna-db-manage so that it checks the db connection info and throws a polite error to the user for attempted migrations on unsupported platforms. For example: Database migrations are not supported for sqlite Because, as a developer, when I see a sql error trace as the result of an operation I assume it's broken :)
Re: [openstack-dev] savann-ci, Re: [savanna] Alembic migrations and absence of DROP column in sqlite
Hi I'm currently working on moving on the MySQL for savanna-ci We are working on same task in ceilometer so maybe you could use some of our patches as reference: https://review.openstack.org/#/c/59489/ https://review.openstack.org/#/c/63049/ Regards, Alexei On 02/05/2014 02:06 PM, Sergey Kolekonov wrote: I'm currently working on moving on the MySQL for savanna-ci On Wed, Feb 5, 2014 at 3:53 PM, Sergey Lukjanov slukja...@mirantis.com mailto:slukja...@mirantis.com wrote: Agreed, let's move on to the MySQL for savanna-ci to run integration tests against production-like DB. On Wed, Feb 5, 2014 at 1:54 AM, Andrew Lazarev alaza...@mirantis.com mailto:alaza...@mirantis.com wrote: Since sqlite is not in the list of databases that would be used in production, CI should use other DB for testing. Andrew. On Tue, Feb 4, 2014 at 1:13 PM, Alexander Ignatov aigna...@mirantis.com mailto:aigna...@mirantis.com wrote: Indeed. We should create a bug around that and move our savanna-ci to mysql. Regards, Alexander Ignatov On 05 Feb 2014, at 01:01, Trevor McKay tmc...@redhat.com mailto:tmc...@redhat.com wrote: This brings up an interesting problem: In https://review.openstack.org/#/c/70420/ I've added a migration that uses a drop column for an upgrade. But savann-ci is apparently using a sqlite database to run. So it can't possibly pass. What do we do here? Shift savanna-ci tests to non sqlite? Trevor On Sat, 2014-02-01 at 18:17 +0200, Roman Podoliaka wrote: Hi all, My two cents. 2) Extend alembic so that op.drop_column() does the right thing We could, but should we? The only reason alembic doesn't support these operations for SQLite yet is that SQLite lacks proper support of ALTER statement. For sqlalchemy-migrate we've been providing a work-around in the form of recreating of a table and copying of all existing rows (which is a hack, really). But to be able to recreate a table, we first must have its definition. And we've been relying on SQLAlchemy schema reflection facilities for that. Unfortunately, this approach has a few drawbacks: 1) SQLAlchemy versions prior to 0.8.4 don't support reflection of unique constraints, which means the recreated table won't have them; 2) special care must be taken in 'edge' cases (e.g. when you want to drop a BOOLEAN column, you must also drop the corresponding CHECK (col in (0, 1)) constraint manually, or SQLite will raise an error when the table is recreated without the column being dropped) 3) special care must be taken for 'custom' type columns (it's got better with SQLAlchemy 0.8.x, but e.g. in 0.7.x we had to override definitions of reflected BIGINT columns manually for each column.drop() call) 4) schema reflection can't be performed when alembic migrations are run in 'offline' mode (without connecting to a DB) ... (probably something else I've forgotten) So it's totally doable, but, IMO, there is no real benefit in supporting running of schema migrations for SQLite. ...attempts to drop schema generation based on models in favor of migrations As long as we have a test that checks that the DB schema obtained by running of migration scripts is equal to the one obtained by calling metadata.create_all(), it's perfectly OK to use model definitions to generate the initial DB schema for running of unit-tests as well as for new installations of OpenStack (and this is actually faster than running of migration scripts). ... and if we have strong objections against doing metadata.create_all(), we can always use migration scripts for both new installations and upgrades for all DB backends, except SQLite. Thanks, Roman On Sat, Feb 1, 2014 at 12:09 PM, Eugene Nikanorov
Re: [openstack-dev] savann-ci, Re: [savanna] Alembic migrations and absence of DROP column in sqlite
It's about integration tests that aren't db-specific, so, just DATABASE/connection should be fixed ;) On Wed, Feb 5, 2014 at 4:33 PM, Alexei Kornienko alexei.kornie...@gmail.com wrote: Hi I'm currently working on moving on the MySQL for savanna-ci We are working on same task in ceilometer so maybe you could use some of our patches as reference: https://review.openstack.org/#/c/59489/ https://review.openstack.org/#/c/63049/ Regards, Alexei On 02/05/2014 02:06 PM, Sergey Kolekonov wrote: I'm currently working on moving on the MySQL for savanna-ci On Wed, Feb 5, 2014 at 3:53 PM, Sergey Lukjanov slukja...@mirantis.comwrote: Agreed, let's move on to the MySQL for savanna-ci to run integration tests against production-like DB. On Wed, Feb 5, 2014 at 1:54 AM, Andrew Lazarev alaza...@mirantis.comwrote: Since sqlite is not in the list of databases that would be used in production, CI should use other DB for testing. Andrew. On Tue, Feb 4, 2014 at 1:13 PM, Alexander Ignatov aigna...@mirantis.com wrote: Indeed. We should create a bug around that and move our savanna-ci to mysql. Regards, Alexander Ignatov On 05 Feb 2014, at 01:01, Trevor McKay tmc...@redhat.com wrote: This brings up an interesting problem: In https://review.openstack.org/#/c/70420/ I've added a migration that uses a drop column for an upgrade. But savann-ci is apparently using a sqlite database to run. So it can't possibly pass. What do we do here? Shift savanna-ci tests to non sqlite? Trevor On Sat, 2014-02-01 at 18:17 +0200, Roman Podoliaka wrote: Hi all, My two cents. 2) Extend alembic so that op.drop_column() does the right thing We could, but should we? The only reason alembic doesn't support these operations for SQLite yet is that SQLite lacks proper support of ALTER statement. For sqlalchemy-migrate we've been providing a work-around in the form of recreating of a table and copying of all existing rows (which is a hack, really). But to be able to recreate a table, we first must have its definition. And we've been relying on SQLAlchemy schema reflection facilities for that. Unfortunately, this approach has a few drawbacks: 1) SQLAlchemy versions prior to 0.8.4 don't support reflection of unique constraints, which means the recreated table won't have them; 2) special care must be taken in 'edge' cases (e.g. when you want to drop a BOOLEAN column, you must also drop the corresponding CHECK (col in (0, 1)) constraint manually, or SQLite will raise an error when the table is recreated without the column being dropped) 3) special care must be taken for 'custom' type columns (it's got better with SQLAlchemy 0.8.x, but e.g. in 0.7.x we had to override definitions of reflected BIGINT columns manually for each column.drop() call) 4) schema reflection can't be performed when alembic migrations are run in 'offline' mode (without connecting to a DB) ... (probably something else I've forgotten) So it's totally doable, but, IMO, there is no real benefit in supporting running of schema migrations for SQLite. ...attempts to drop schema generation based on models in favor of migrations As long as we have a test that checks that the DB schema obtained by running of migration scripts is equal to the one obtained by calling metadata.create_all(), it's perfectly OK to use model definitions to generate the initial DB schema for running of unit-tests as well as for new installations of OpenStack (and this is actually faster than running of migration scripts). ... and if we have strong objections against doing metadata.create_all(), we can always use migration scripts for both new installations and upgrades for all DB backends, except SQLite. Thanks, Roman On Sat, Feb 1, 2014 at 12:09 PM, Eugene Nikanorov enikano...@mirantis.com wrote: Boris, Sorry for the offtopic. Is switching to model-based schema generation is something decided? I see the opposite: attempts to drop schema generation based on models in favor of migrations. Can you point to some discussion threads? Thanks, Eugene. On Sat, Feb 1, 2014 at 2:19 AM, Boris Pavlovic bpavlo...@mirantis.com wrote: Jay, Yep we shouldn't use migrations for sqlite at all. The major issue that we have now is that we are not able to ensure that DB schema created by migration models are same (actually they are not same). So before dropping support of migrations for sqlite switching to model based created schema we should add tests that will check that model migrations are synced. (we are working on this) Best regards, Boris Pavlovic On Fri, Jan 31, 2014 at 7:31 PM, Andrew Lazarev alaza...@mirantis.com wrote: Trevor, Such check could be useful on alembic side too. Good opportunity for contribution. Andrew. On Fri, Jan 31, 2014 at
Re: [openstack-dev] savann-ci, Re: [savanna] Alembic migrations and absence of DROP column in sqlite
Hi Sergey, Is there a bug or a blueprint for this? I did a quick search but didn't see one. Thanks, Trevor On Wed, 2014-02-05 at 16:06 +0400, Sergey Kolekonov wrote: I'm currently working on moving on the MySQL for savanna-ci On Wed, Feb 5, 2014 at 3:53 PM, Sergey Lukjanov slukja...@mirantis.com wrote: Agreed, let's move on to the MySQL for savanna-ci to run integration tests against production-like DB. On Wed, Feb 5, 2014 at 1:54 AM, Andrew Lazarev alaza...@mirantis.com wrote: Since sqlite is not in the list of databases that would be used in production, CI should use other DB for testing. Andrew. On Tue, Feb 4, 2014 at 1:13 PM, Alexander Ignatov aigna...@mirantis.com wrote: Indeed. We should create a bug around that and move our savanna-ci to mysql. Regards, Alexander Ignatov On 05 Feb 2014, at 01:01, Trevor McKay tmc...@redhat.com wrote: This brings up an interesting problem: In https://review.openstack.org/#/c/70420/ I've added a migration that uses a drop column for an upgrade. But savann-ci is apparently using a sqlite database to run. So it can't possibly pass. What do we do here? Shift savanna-ci tests to non sqlite? Trevor On Sat, 2014-02-01 at 18:17 +0200, Roman Podoliaka wrote: Hi all, My two cents. 2) Extend alembic so that op.drop_column() does the right thing We could, but should we? The only reason alembic doesn't support these operations for SQLite yet is that SQLite lacks proper support of ALTER statement. For sqlalchemy-migrate we've been providing a work-around in the form of recreating of a table and copying of all existing rows (which is a hack, really). But to be able to recreate a table, we first must have its definition. And we've been relying on SQLAlchemy schema reflection facilities for that. Unfortunately, this approach has a few drawbacks: 1) SQLAlchemy versions prior to 0.8.4 don't support reflection of unique constraints, which means the recreated table won't have them; 2) special care must be taken in 'edge' cases (e.g. when you want to drop a BOOLEAN column, you must also drop the corresponding CHECK (col in (0, 1)) constraint manually, or SQLite will raise an error when the table is recreated without the column being dropped) 3) special care must be taken for 'custom' type columns (it's got better with SQLAlchemy 0.8.x, but e.g. in 0.7.x we had to override definitions of reflected BIGINT columns manually for each column.drop() call) 4) schema reflection can't be performed when alembic migrations are run in 'offline' mode (without connecting to a DB) ... (probably something else I've forgotten) So it's totally doable, but, IMO, there is
Re: [openstack-dev] savann-ci, Re: [savanna] Alembic migrations and absence of DROP column in sqlite
Trevor, I've created an issue to track it https://bugs.launchpad.net/savanna/+bug/1276764 On Wed, Feb 5, 2014 at 8:56 PM, Trevor McKay tmc...@redhat.com wrote: Hi Sergey, Is there a bug or a blueprint for this? I did a quick search but didn't see one. Thanks, Trevor On Wed, 2014-02-05 at 16:06 +0400, Sergey Kolekonov wrote: I'm currently working on moving on the MySQL for savanna-ci On Wed, Feb 5, 2014 at 3:53 PM, Sergey Lukjanov slukja...@mirantis.com wrote: Agreed, let's move on to the MySQL for savanna-ci to run integration tests against production-like DB. On Wed, Feb 5, 2014 at 1:54 AM, Andrew Lazarev alaza...@mirantis.com wrote: Since sqlite is not in the list of databases that would be used in production, CI should use other DB for testing. Andrew. On Tue, Feb 4, 2014 at 1:13 PM, Alexander Ignatov aigna...@mirantis.com wrote: Indeed. We should create a bug around that and move our savanna-ci to mysql. Regards, Alexander Ignatov On 05 Feb 2014, at 01:01, Trevor McKay tmc...@redhat.com wrote: This brings up an interesting problem: In https://review.openstack.org/#/c/70420/ I've added a migration that uses a drop column for an upgrade. But savann-ci is apparently using a sqlite database to run. So it can't possibly pass. What do we do here? Shift savanna-ci tests to non sqlite? Trevor On Sat, 2014-02-01 at 18:17 +0200, Roman Podoliaka wrote: Hi all, My two cents. 2) Extend alembic so that op.drop_column() does the right thing We could, but should we? The only reason alembic doesn't support these operations for SQLite yet is that SQLite lacks proper support of ALTER statement. For sqlalchemy-migrate we've been providing a work-around in the form of recreating of a table and copying of all existing rows (which is a hack, really). But to be able to recreate a table, we first must have its definition. And we've been relying on SQLAlchemy schema reflection facilities for that. Unfortunately, this approach has a few drawbacks: 1) SQLAlchemy versions prior to 0.8.4 don't support reflection of unique constraints, which means the recreated table won't have them; 2) special care must be taken in 'edge' cases (e.g. when you want to drop a BOOLEAN column, you must also drop the corresponding CHECK (col in (0, 1)) constraint manually, or SQLite will raise an error when the table is recreated without the column being dropped) 3) special care must be taken for 'custom' type columns (it's got better with SQLAlchemy 0.8.x, but e.g. in 0.7.x we had to override definitions of reflected BIGINT columns manually for each column.drop() call) 4) schema reflection can't be performed when alembic migrations are run in 'offline' mode (without connecting to a DB) ... (probably something else I've forgotten)
Re: [openstack-dev] savann-ci, Re: [savanna] Alembic migrations and absence of DROP column in sqlite
Indeed. We should create a bug around that and move our savanna-ci to mysql. Regards, Alexander Ignatov On 05 Feb 2014, at 01:01, Trevor McKay tmc...@redhat.com wrote: This brings up an interesting problem: In https://review.openstack.org/#/c/70420/ I've added a migration that uses a drop column for an upgrade. But savann-ci is apparently using a sqlite database to run. So it can't possibly pass. What do we do here? Shift savanna-ci tests to non sqlite? Trevor On Sat, 2014-02-01 at 18:17 +0200, Roman Podoliaka wrote: Hi all, My two cents. 2) Extend alembic so that op.drop_column() does the right thing We could, but should we? The only reason alembic doesn't support these operations for SQLite yet is that SQLite lacks proper support of ALTER statement. For sqlalchemy-migrate we've been providing a work-around in the form of recreating of a table and copying of all existing rows (which is a hack, really). But to be able to recreate a table, we first must have its definition. And we've been relying on SQLAlchemy schema reflection facilities for that. Unfortunately, this approach has a few drawbacks: 1) SQLAlchemy versions prior to 0.8.4 don't support reflection of unique constraints, which means the recreated table won't have them; 2) special care must be taken in 'edge' cases (e.g. when you want to drop a BOOLEAN column, you must also drop the corresponding CHECK (col in (0, 1)) constraint manually, or SQLite will raise an error when the table is recreated without the column being dropped) 3) special care must be taken for 'custom' type columns (it's got better with SQLAlchemy 0.8.x, but e.g. in 0.7.x we had to override definitions of reflected BIGINT columns manually for each column.drop() call) 4) schema reflection can't be performed when alembic migrations are run in 'offline' mode (without connecting to a DB) ... (probably something else I've forgotten) So it's totally doable, but, IMO, there is no real benefit in supporting running of schema migrations for SQLite. ...attempts to drop schema generation based on models in favor of migrations As long as we have a test that checks that the DB schema obtained by running of migration scripts is equal to the one obtained by calling metadata.create_all(), it's perfectly OK to use model definitions to generate the initial DB schema for running of unit-tests as well as for new installations of OpenStack (and this is actually faster than running of migration scripts). ... and if we have strong objections against doing metadata.create_all(), we can always use migration scripts for both new installations and upgrades for all DB backends, except SQLite. Thanks, Roman On Sat, Feb 1, 2014 at 12:09 PM, Eugene Nikanorov enikano...@mirantis.com wrote: Boris, Sorry for the offtopic. Is switching to model-based schema generation is something decided? I see the opposite: attempts to drop schema generation based on models in favor of migrations. Can you point to some discussion threads? Thanks, Eugene. On Sat, Feb 1, 2014 at 2:19 AM, Boris Pavlovic bpavlo...@mirantis.com wrote: Jay, Yep we shouldn't use migrations for sqlite at all. The major issue that we have now is that we are not able to ensure that DB schema created by migration models are same (actually they are not same). So before dropping support of migrations for sqlite switching to model based created schema we should add tests that will check that model migrations are synced. (we are working on this) Best regards, Boris Pavlovic On Fri, Jan 31, 2014 at 7:31 PM, Andrew Lazarev alaza...@mirantis.com wrote: Trevor, Such check could be useful on alembic side too. Good opportunity for contribution. Andrew. On Fri, Jan 31, 2014 at 6:12 AM, Trevor McKay tmc...@redhat.com wrote: Okay, I can accept that migrations shouldn't be supported on sqlite. However, if that's the case then we need to fix up savanna-db-manage so that it checks the db connection info and throws a polite error to the user for attempted migrations on unsupported platforms. For example: Database migrations are not supported for sqlite Because, as a developer, when I see a sql error trace as the result of an operation I assume it's broken :) Best, Trevor On Thu, 2014-01-30 at 15:04 -0500, Jay Pipes wrote: On Thu, 2014-01-30 at 14:51 -0500, Trevor McKay wrote: I was playing with alembic migration and discovered that op.drop_column() doesn't work with sqlite. This is because sqlite doesn't support dropping a column (broken imho, but that's another discussion). Sqlite throws a syntax error. To make this work with sqlite, you have to copy the table to a temporary excluding the column(s) you don't want and delete the old one, followed by a rename of the new table. The existing 002 migration uses op.drop_column(), so I'm assuming it's broken, too (I need to
Re: [openstack-dev] savann-ci, Re: [savanna] Alembic migrations and absence of DROP column in sqlite
Since sqlite is not in the list of databases that would be used in production, CI should use other DB for testing. Andrew. On Tue, Feb 4, 2014 at 1:13 PM, Alexander Ignatov aigna...@mirantis.comwrote: Indeed. We should create a bug around that and move our savanna-ci to mysql. Regards, Alexander Ignatov On 05 Feb 2014, at 01:01, Trevor McKay tmc...@redhat.com wrote: This brings up an interesting problem: In https://review.openstack.org/#/c/70420/ I've added a migration that uses a drop column for an upgrade. But savann-ci is apparently using a sqlite database to run. So it can't possibly pass. What do we do here? Shift savanna-ci tests to non sqlite? Trevor On Sat, 2014-02-01 at 18:17 +0200, Roman Podoliaka wrote: Hi all, My two cents. 2) Extend alembic so that op.drop_column() does the right thing We could, but should we? The only reason alembic doesn't support these operations for SQLite yet is that SQLite lacks proper support of ALTER statement. For sqlalchemy-migrate we've been providing a work-around in the form of recreating of a table and copying of all existing rows (which is a hack, really). But to be able to recreate a table, we first must have its definition. And we've been relying on SQLAlchemy schema reflection facilities for that. Unfortunately, this approach has a few drawbacks: 1) SQLAlchemy versions prior to 0.8.4 don't support reflection of unique constraints, which means the recreated table won't have them; 2) special care must be taken in 'edge' cases (e.g. when you want to drop a BOOLEAN column, you must also drop the corresponding CHECK (col in (0, 1)) constraint manually, or SQLite will raise an error when the table is recreated without the column being dropped) 3) special care must be taken for 'custom' type columns (it's got better with SQLAlchemy 0.8.x, but e.g. in 0.7.x we had to override definitions of reflected BIGINT columns manually for each column.drop() call) 4) schema reflection can't be performed when alembic migrations are run in 'offline' mode (without connecting to a DB) ... (probably something else I've forgotten) So it's totally doable, but, IMO, there is no real benefit in supporting running of schema migrations for SQLite. ...attempts to drop schema generation based on models in favor of migrations As long as we have a test that checks that the DB schema obtained by running of migration scripts is equal to the one obtained by calling metadata.create_all(), it's perfectly OK to use model definitions to generate the initial DB schema for running of unit-tests as well as for new installations of OpenStack (and this is actually faster than running of migration scripts). ... and if we have strong objections against doing metadata.create_all(), we can always use migration scripts for both new installations and upgrades for all DB backends, except SQLite. Thanks, Roman On Sat, Feb 1, 2014 at 12:09 PM, Eugene Nikanorov enikano...@mirantis.com wrote: Boris, Sorry for the offtopic. Is switching to model-based schema generation is something decided? I see the opposite: attempts to drop schema generation based on models in favor of migrations. Can you point to some discussion threads? Thanks, Eugene. On Sat, Feb 1, 2014 at 2:19 AM, Boris Pavlovic bpavlo...@mirantis.com wrote: Jay, Yep we shouldn't use migrations for sqlite at all. The major issue that we have now is that we are not able to ensure that DB schema created by migration models are same (actually they are not same). So before dropping support of migrations for sqlite switching to model based created schema we should add tests that will check that model migrations are synced. (we are working on this) Best regards, Boris Pavlovic On Fri, Jan 31, 2014 at 7:31 PM, Andrew Lazarev alaza...@mirantis.com wrote: Trevor, Such check could be useful on alembic side too. Good opportunity for contribution. Andrew. On Fri, Jan 31, 2014 at 6:12 AM, Trevor McKay tmc...@redhat.com wrote: Okay, I can accept that migrations shouldn't be supported on sqlite. However, if that's the case then we need to fix up savanna-db-manage so that it checks the db connection info and throws a polite error to the user for attempted migrations on unsupported platforms. For example: Database migrations are not supported for sqlite Because, as a developer, when I see a sql error trace as the result of an operation I assume it's broken :) Best, Trevor On Thu, 2014-01-30 at 15:04 -0500, Jay Pipes wrote: On Thu, 2014-01-30 at 14:51 -0500, Trevor McKay wrote: I was playing with alembic migration and discovered that op.drop_column() doesn't work with sqlite. This is because sqlite doesn't support dropping a column (broken imho, but that's another
