Hi Alex, Thanks for the update. The PR looks good to me now.
Creating a document to list all source-of-truth schema files in the Git rep works for now. We can address any further improvements as follow-ups. Yufei On Fri, Sep 25, 2026 at 2:28 PM Prithvi S <[email protected]> wrote: > Hi all, > > +1 on landing #5349 this way. The version check belongs with the single > schema.sql, and the upgrade notes can wait. > > The page still says to apply the migration SQL below, and that SQL is gone. > What's left is a diff of schema.sql, from v6 on. > I think we should still give people some SQL. A schema diff shows the end > state, not what to run when the tables already have data. > idempotency_records only exists in v4, and the v5 file says it was never > wired up. v3 to v5 has nothing to do for that table. Running every hop > creates it and then drops it. On a real v4 database, DROP TABLE IF EXISTS > is enough, index and primary key included. I'd only list a dependency when > the drop changes some other table we're keeping, like Ayush said. > Same kind of gap elsewhere. The 1.7 events change needs an UPDATE to clear > '__realm__', and a schema diff only shows the nullable column. The v6 notes > drop and recreate idx_locations, and Cockroach needs indexes even when > version already says 6. #5349 checks that number, so the database still > starts. > #5437 already added the idempotency drop on the published 1.7.0 page. The > changelog and the doc on main never picked it up. > So a short note per release, only for those steps. New tables and columns > come from the diff. Anything added and removed in between can be skipped. > > I'd keep the SQL as a file in the repo and test it the way JB described. > Load the old schema, run the file, check columns and indexes against the > next schema. The doc links the file. > > Thanks, > Prithvi S > > On Fri, Sep 25, 2026 at 6:53 PM Dmitri Bourlatchkov <[email protected]> > wrote: > > > Hi All, > > > > Alex's proposal for making progress here sounds good to me. +1 to PR > [5349] > > in its current state. > > > > I think it is also a good idea to reopen the discussion on schema upgrade > > instructions after merging this PR. > > > > [5349] https://github.com/apache/polaris/pull/5349 > > > > Cheers, > > Dmitri. > > > > On Fri, Sep 25, 2026 at 9:03 AM Alex Dutra <[email protected]> wrote: > > > > > Hi Yufei, hi all, > > > > > > In [5349], I do believe that the instructions were complete and > correct. > > > > > > However, in the spirit of making progress in that PR, which is stuck > > > until we settle on this specific topic, I went ahead and removed ALL > > > migration SQL snippets from that PR, **including** what was already > > > present on main, as you requested. Only generic instructions about how > > > to get the schema diffs were retained. > > > > > > I hope this move will help get that PR unstuck. > > > > > > But now I think this discussion thread (or a new one maybe) should > > > answer a broader question: should we provide any form of specific SQL > > > migration guidance to users, and if so, in what form? > > > > > > Thanks, > > > Alex > > > > > > [5349]: https://github.com/apache/polaris/pull/5349 > > > > > > > > > On Thu, Sep 24, 2026 at 10:53 PM Yufei Gu <[email protected]> > wrote: > > > > > > > > > That's a net loss for end users. > > > > > > > > This assumes the documented instructions are correct and sufficient > to > > > > complete the upgrade. I don’t think that’s the case. For example, > what > > > > steps should users follow to upgrade from a schema version earlier > than > > > v4 > > > > to v5? Why do users need to create a table and then delete it during > a > > > > upgrade? It is getting even more complex when data backfill is > needed. > > > In a > > > > real env, users still need to consult the versioned schema files,* > the > > > > source of truth*, to understand what has changed. > > > > > > > > Schema upgrades are critical operations that require great care; > even a > > > > small error can break the system. Given these gaps, I don’t think > users > > > can > > > > confidently rely solely on the Schema upgrades section > > > > < > > > > > > https://polaris.apache.org/releases/1.7.0/metastores/relational-jdbc/#schema-upgrades > > > > > > > > . > > > > > > > > Maintaining separate migration instructions also adds a maintenance > > > burden > > > > for the community when we already have the source of truth in the > rep. > > > > Besides, incomplete instructions can give users a false sense of > > > confidence > > > > that following the page is sufficient for a safe upgrade, which is > > > > disastrous. > > > > > > > > Yufei > > > > > > > > > > > > On Wed, Sep 23, 2026 at 6:06 AM Alex Dutra <[email protected]> > wrote: > > > > > > > > > Hi Yufei, > > > > > > > > > > > This fails on older schemas that don't have the events table. > > > > > > > > > > If a user follows the migrations sequentially, the events table is > > > > > guaranteed to exist by the time the v4 to v5 script runs. The > UPDATE > > > > > statement only fails if someone tries to apply the v4 to v5 > migration > > > > > on a schema that never went through previous steps. That's an > > operator > > > > > error, not a documentation issue. > > > > > > > > > > > I'd suggest removing the entire Schema upgrades section > > > > > > > > > > That's a net loss for end users. Why not keep it? I agree it's > > subject > > > > > to drift, but as I mentioned earlier, 1) it's still better than > > > > > nothing, and 2) we can prevent drift by creating migration tests > that > > > > > exercise the migration steps. > > > > > > > > > > Thanks, > > > > > Alex > > > > > > > > > > On Wed, Sep 23, 2026 at 5:18 AM Yong Zheng <[email protected]> > > wrote: > > > > > > > > > > > > Thanks for the feedback all. I will proceed with the change. > > > > > > > > > > > > Thanks, > > > > > > Yong > > > > > > > > > > > > On 2026/09/22 23:45:05 Yufei Gu wrote: > > > > > > > I think users shouldn't rely on SQL snippets in the upgrade > guide > > > as > > > > > the > > > > > > > source of truth for schema changes. > > > > > > > > > > > > > > For example: UPDATE polaris_schema.events SET catalog_id = NULL > > > WHERE > > > > > > > catalog_id = '__realm__'; > > > > > > > This fails on older schemas that don't have the events table. > > Like > > > the > > > > > > > ALTER TABLE example discussed above, it shows why migration > steps > > > need > > > > > to > > > > > > > account for the starting schema version. > > > > > > > > > > > > > > I'd suggest removing the entire Schema upgrades section > > > > > > > < > > > > > > > > > > > https://polaris.apache.org/releases/1.7.0/metastores/relational-jdbc/#schema-upgrades > > > > > >. > > > > > > > The historical schema SQL files should remain the source of > truth > > > for > > > > > each > > > > > > > schema version. Maintaining migration SQL separately in the > > > > > documentation > > > > > > > is prone to errors and drift. > > > > > > > > > > > > > > > > > > > > > On Tue, Sep 22, 2026 at 10:40 AM Alex Dutra <[email protected] > > > > > wrote: > > > > > > > > > > > > > > > Hi all, > > > > > > > > > > > > > > > > I agree with Ayush. For the record, I initially included a > DROP > > > INDEX > > > > > > > > statement in my own PR [5349], but in hindsight, I think that > > > was a > > > > > > > > bad idea that sparked this whole discussion. I apologize for > > > that. > > > > > > > > > > > > > > > > > #5349 removes the runtime fallback and makes the migration > > > > > mandatory > > > > > > > > with a fail fast on version mismatch. That turns these > snippets > > > from > > > > > > > > advisory into load bearing, and today they are > > > > > > > > untested prose [...] the durable fix is a test per backend > > > > > > > > > > > > > > > > +1000. That is my intention as soon as [5349] gets merged. I > > > think we > > > > > > > > can also improve on the visual presentation and propose > > migration > > > > > > > > steps for each database type, using Docsy tabbed panes [1]. > But > > > that > > > > > > > > PR is already big, so I think we need to move forward > > > incrementally > > > > > > > > here. > > > > > > > > > > > > > > > > Thanks, > > > > > > > > Alex > > > > > > > > > > > > > > > > [1]: > > https://www.docsy.dev/docs/content/shortcodes/#tabbed-panes > > > > > > > > [5349]: https://github.com/apache/polaris/pull/5349 > > > > > > > > > > > > > > > > On Tue, Sep 22, 2026 at 6:30 AM Jean-Baptiste Onofré < > > > > > [email protected]> > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > Hi guys, > > > > > > > > > > > > > > > > > > +1 to what Ayush said: I would keep the upgrade as a single > > > DROP > > > > > TABLE IF > > > > > > > > > EXISTS polaris_schema.idempotency_records. > > > > > > > > > > > > > > > > > > The decisive argument for me is that the block is > documented > > as > > > > > covering > > > > > > > > > "an existing v3/v4 database". One snippet, two source > > > versions, so > > > > > every > > > > > > > > > statement in it has to be a no-op on the lower one. v3 > never > > > had > > > > > > > > > idempotency_records (it is created in the v3 -> v4 > section), > > so > > > > > ALTER > > > > > > > > TABLE > > > > > > > > > ... DROP CONSTRAINT idempotency_records_pkey fails there, > and > > > with > > > > > > > > > ON_ERROR_STOP the rest of the "migration" never runs. DROP > > > TABLE IF > > > > > > > > EXISTS > > > > > > > > > is a no-op on v3 and correct on v4. That property is worth > > > more to > > > > > > > > > operators than explicitness. > > > > > > > > > > > > > > > > > > On the revert motivation: drop statements do not record how > > to > > > > > recreate > > > > > > > > > anything. A "downgrade" needs the CREATE statements, and > > those > > > > > already > > > > > > > > > exist in schema-v4.sql and are repeated in the v3 -> v4 > > > section of > > > > > #5349. > > > > > > > > > Listing more drops adds nothing there imho. If we want > > > documented > > > > > > > > downgrade > > > > > > > > > later, it should be its own script of CREATE statements. > > > > > > > > > > > > > > > > > > Also, idempotency_records_pkey is just the PostgreSQL > default > > > > > constraint > > > > > > > > > name. A deployment where the constraint was created under a > > > > > different > > > > > > > > name > > > > > > > > > fails the ALTER and succeeds on the DROP TABLE. We claim > > > > > PostgreSQL, > > > > > > > > > CockroachDB and H2 for this block, so I would avoid > generated > > > > > names in > > > > > > > > > operator facing SQL. > > > > > > > > > > > > > > > > > > As a convention, Ayush carve-out is the right line: list a > > > > > dependency > > > > > > > > only > > > > > > > > > when the drop reaches outside the object being removed, > > > typically a > > > > > > > > foreign > > > > > > > > > key from a table we are keeping, where CASCADE silently > > alters > > > that > > > > > > > > > retained table. That is an operator visible side effect and > > > > > belongs in > > > > > > > > the > > > > > > > > > instructions. Cascades confined to the dropped object are > > > noise. > > > > > > > > > > > > > > > > > > One broader point while we are here: #5349 removes the > > runtime > > > > > fallback > > > > > > > > and > > > > > > > > > makes the migration mandatory with a fail fast on version > > > > > mismatch. That > > > > > > > > > turns these snippets from advisory into load bearing, and > > today > > > > > they are > > > > > > > > > untested prose (which is how a statement that errors on > > > PostgreSQL > > > > > got as > > > > > > > > > far as it did). I think the durable fix is a test per > > backend: > > > > > bootstrap > > > > > > > > > schema-vN, apply the documented N -> N+1 SQL, assert the > > result > > > > > matches > > > > > > > > > schema-v(N+1). That would catch this class of issue in CI > > > rather > > > > > than on > > > > > > > > > the list. Happy to open an issue for it. > > > > > > > > > > > > > > > > > > Regards > > > > > > > > > JB > > > > > > > > > > > > > > > > > > On Tue, Sep 22, 2026 at 4:16 AM Yong Zheng < > > [email protected]> > > > > > wrote: > > > > > > > > > > > > > > > > > > > Hello all, > > > > > > > > > > > > > > > > > > > > I would like to start this discussion regarding if we > > should > > > > > list out > > > > > > > > > > cascading dependency deletion during schema version > change > > > (see > > > > > sample > > > > > > > > > > reference in https://github.com/apache/polaris/pull/5437 > ). > > > > > > > > > > > > > > > > > > > > With the sample reference, we will be dropping table > > > > > > > > > > polaris_schema.idempotency_records which has index > > > > > > > > > > "polaris_schema.idx_idemp_realm_expires" and PK on > > > > > > > > > > "idempotency_records_pkey". > > > > > > > > > > > > > > > > > > > > When we drop the table, it would drop the PK along with > > index > > > > > during > > > > > > > > > > cascading dependency deletion. One reason to keep those > is > > to > > > > > easy the > > > > > > > > > > revert process if we need to do so. However, keeping all > of > > > the > > > > > > > > > > dependencies listed out is a bit tedious and add > over-head > > > for > > > > > regular > > > > > > > > > > schema upgrade (in this case, instead of running one drop > > > sql, > > > > > we would > > > > > > > > > > need to do 2 drop plus 1 alter table sql statements). > > > Thoughts? > > > > > > > > > > > > > > > > > > > > Thanks, > > > > > > > > > > Yong > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
