Schema change to add DecompressedLength column to Resource table #5247
Conversation
rajithaalurims
added
Enhancement
| ,@TokenQuantityCompositeSearchParams dbo.TokenQuantityCompositeSearchParamList READONLY | ||
| ,@TokenStringCompositeSearchParams dbo.TokenStringCompositeSearchParamList READONLY | ||
| ,@TokenNumberNumberCompositeSearchParams dbo.TokenNumberNumberCompositeSearchParamList READONLY | ||
| ,@DecompressedOverridesJson NVARCHAR(MAX) = NULL |
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Parsing JSON on each merge call sounds expensive. Instead, we should add decompressed length to ResourceList table type. There should be multiple iterations to get compatibility and final clean state.
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I was debating between changing ResourceList table type but as you mentioned that needs multiple iterations of code release to get final clean slate.
From what I have researched additional cost for parsing takes around few hundred milli seconds for rows around 10000.
I will discuss offline with you about which option to go with
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Maybe. But imagine that we start adding extra JSON vars for each new column we add... This looks like antipattern. Also, there are extra joins to @Resources, and they are extra cost too... All of these are just not applicable to the case of table type change. BTW You should get fully functioning code on first iteration...
| TransactionId bigint NULL, | ||
| HistoryTransactionId bigint NULL | ||
| HistoryTransactionId bigint NULL, | ||
| DecompressedLength decimal(36,18) NULL |
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Why it cannot be int?
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I should have used INT. I will change
| BEGIN TRY | ||
| INSERT INTO dbo.Parameters (Id, Char) SELECT 'Adding DecompressedLength', 'LogEvent' | ||
| EXECUTE dbo.LogEvent @Process='Adding DecompressedLength',@Status='Start' | ||
| BEGIN TRANSACTION |
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I don't see why transaction is needed. Please explain.
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I want to drop and recreate procedure in the same transaction.
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You don't need to drop/create, but use alter. If you break up the transaction, what negative effects do you expect?
Description
A new Nullable column DecompressedLength added to Resource table.
This will be used to store size of raw resource before compressing it.
This change is both backward and forward compatible.
Checking schema version before passing additional parameter to MergeResource SP to avoid "Procedure or function 'MergeResources' has too many arguments specified." error.
Related issues
Addresses [issue #156583].
Testing
Tested with old code new schema and new code old schema
FHIR Team Checklist
Semver Change (docs)
Patch|Skip|Feature|Breaking (reason)