如何在CrateDB中编辑/删除Analyzer？官方文档相关疑问

First, let's break down the behavior you're seeing with repeated CREATE ANALYZER commands:

• When you run CREATE ANALYZER myanalyzer (TOKENIZER whitespace, TOKEN_FILTERS ( lowercase, kstem ), CHAR_FILTERS ( html_strip )); multiple times without errors, this isn't an oversight—it's intentional behavior. CrateDB treats CREATE ANALYZER as an idempotent operation: if an analyzer with the same name already exists, executing the statement will overwrite its configuration with your new settings. You can verify this easily:
  1. Create the analyzer as you did initially
  2. Test its behavior with ANALYZE myanalyzer 'Hello WORLD <b>Test</b>' to confirm the stemmed, lowercased output
  3. Re-run the create command without the kstem filter: CREATE ANALYZER myanalyzer (TOKENIZER whitespace, TOKEN_FILTERS ( lowercase ), CHAR_FILTERS ( html_strip ));
  4. Run the same ANALYZE command again—you'll notice the stemming effect is gone, proving the analyzer was updated.

Now, onto the deletion question:

• As you observed, CrateDB doesn't currently offer a DROP ANALYZER SQL statement (which is why it's missing from the official docs). There's no direct way to delete a custom analyzer with a single command, but you can work around this based on your scenario:
  • If the analyzer isn't used by any table columns: You can just leave it be—unreferenced custom analyzers take negligible cluster state space and don't affect performance.
  • If the analyzer is actively used: First, update all table columns that reference it using ALTER TABLE ... ALTER COLUMN ... SET (analyzer = 'your_preferred_analyzer') to switch to a different analyzer (or the default). Once the analyzer has no active references, it will still linger in the cluster state; if you need to fully remove it, the only current option is to spin up a new cluster and reindex your data, since there's no way to manually purge unused analyzers from the existing cluster state.

This limitation may be addressed in future CrateDB releases, but as of the latest stable version, this is the expected behavior.

内容的提问来源于stack exchange，提问作者Piyush Chugh