Test inferred schema for json array #454
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Arrow infer schema internally uses IndexMap to keep track of inferred schema while updating it through given json objects. Thus the order in which insertion happens to this map determines the output order for schema fields as well. Since the json object in serde_json uses BtreeMap, the iteration is always ascending by key. This leads to infer_schema producing schema fields in ascending order when we infer using only one json object. In case of json array any new fields encountered are added to the last. Thus output order of infer schema did not provide good enough guarantee. This is solved in parseablehq#450. This commit just adds a test for it.
Sign up for free
to subscribe to this conversation on GitHub.
Already have an account?
Sign in.
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Description
Arrow's infer_json_schema internally uses IndexMap to keep track of inferred schema while it is being updated as it goes through array of json objects. Thus the order in which insertion happens to this map determines the output order for schema fields as well.
Since the json object in serde_json uses BtreeMap, the iteration is always ascending by key. This leads to infer_schema producing schema fields in ascending order when we infer using only one json object. In case of json array any new fields encountered are added to the end of indexmap. Thus output order of infer schema did not provide good enough guarantee.
This is solved in #450. This PR just adds a test for it.
This PR has: