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https://issues.apache.org/jira/browse/IGNITE-15901?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Andrey Mashenkov updated IGNITE-15901:
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Component/s: sql
> Drop Live schema support.
> -------------------------
>
> Key: IGNITE-15901
> URL: https://issues.apache.org/jira/browse/IGNITE-15901
> Project: Ignite
> Issue Type: Bug
> Components: sql
> Reporter: Andrey Mashenkov
> Priority: Major
> Labels: iep-54, ignite-3
> Fix For: 3.0.0-alpha4
>
> Time Spent: 10m
> Remaining Estimate: 0h
>
> h3. Motivation.
> The Live-schema concept looks like a very disputable thing. It may cause
> unwanted schema change if a new/outdated/broken client puts the data to the
> grid. Implicit schema changes may lead to unpredicted behaviour from the user
> perspective.
> In most cases, user application and schema are mutually dependent things.
> Thus, the application model and schema must be changed consistently.
> In the general case, it is impossible to keep the consistency and the
> decision on that must be taken on the user side.
> Actually, there are 2 different use cases for the schema-last approach:
> * The first one, when a user creates a table without specifying a schema and
> Ignite automatically create the initial schema version on the first 'put'
> operation. This may be useful for PoC or tests.
> * The second one, when a user changes data model classes, and Ignite update
> the schema implicitly on the next 'put' operation to make schema match the
> new data model. Here are many limitations we can do transparently without any
> additional configuration from the user side.
> Thus, the first case may be a not too bad idea. However, the second case
> looks error-prone.
> h3. Suggestion.
> Drop LiveSchema mode and remove all the related code.
> Postpone all the related tasks unless we will have clear explanation on how
> it should work and how a user should use it.
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