István Zoltán Szabó
94 lines
2.5 KiB
Plaintext
94 lines
2.5 KiB
Plaintext
[[client-helpers]]
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== Client helpers
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You can find here a collection of simple helper functions that abstract some
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specifics of the raw API. For detailed examples, refer to
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https://elasticsearch-py.readthedocs.io/en/stable/helpers.html[this page].
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[discrete]
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[[bulk-helpers]]
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=== Bulk helpers
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There are several helpers for the bulk API since its requirement for specific
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formatting and other considerations can make it cumbersome if used directly.
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All bulk helpers accept an instance of `{es}` class and an iterable `action`
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(any iterable, can also be a generator, which is ideal in most cases since it
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allows you to index large datasets without the need of loading them into
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memory).
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The items in the iterable `action` should be the documents we wish to index in
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several formats. The most common one is the same as returned by `search()`, for
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example:
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[source,yml]
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----------------------------
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{
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'_index': 'index-name',
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'_type': 'document',
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'_id': 42,
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'_routing': 5,
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'pipeline': 'my-ingest-pipeline',
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'_source': {
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"title": "Hello World!",
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"body": "..."
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}
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}
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----------------------------
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Alternatively, if `_source` is not present, it pops all metadata fields from
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the doc and use the rest as the document data:
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[source,yml]
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----------------------------
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{
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"_id": 42,
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"_routing": 5,
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"title": "Hello World!",
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"body": "..."
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}
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----------------------------
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The `bulk()` api accepts `index`, `create`, `delete`, and `update` actions. Use
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the `_op_type` field to specify an action (`_op_type` defaults to `index`):
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[source,yml]
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----------------------------
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{
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'_op_type': 'delete',
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'_index': 'index-name',
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'_type': 'document',
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'_id': 42,
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}
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{
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'_op_type': 'update',
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'_index': 'index-name',
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'_type': 'document',
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'_id': 42,
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'doc': {'question': 'The life, universe and everything.'}
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}
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----------------------------
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[discrete]
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[[scan]]
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=== Scan
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Simple abstraction on top of the `scroll()` API - a simple iterator that yields
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all hits as returned by underlining scroll requests.
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By default scan does not return results in any pre-determined order. To have a
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standard order in the returned documents (either by score or explicit sort
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definition) when scrolling, use `preserve_order=True`. This may be an expensive
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operation and will negate the performance benefits of using `scan`.
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[source,py]
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----------------------------
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scan(es,
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query={"query": {"match": {"title": "python"}}},
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index="orders-*",
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doc_type="books"
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)
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---------------------------- |