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new 8b58277540 Docs: Enhance create_changelog_view usage (#9889)
8b58277540 is described below
commit 8b58277540fb9c5bc1936dcbc1a13793a72a6fee
Author: Manu Zhang <[email protected]>
AuthorDate: Thu Mar 14 00:54:20 2024 +0800
Docs: Enhance create_changelog_view usage (#9889)
---
docs/docs/spark-procedures.md | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/docs/docs/spark-procedures.md b/docs/docs/spark-procedures.md
index ee8a8466c7..7dc0d1a2aa 100644
--- a/docs/docs/spark-procedures.md
+++ b/docs/docs/spark-procedures.md
@@ -756,8 +756,8 @@ Creates a view that contains the changes from a given table.
| `table` | ✔️ | string | Name of the source
table for the changelog
|
| `changelog_view` | | string | Name of the view to
create
|
| `options` | | map<string, string> | A map of Spark read
options to use
|
-| `net_changes` | | boolean | Whether to output
net changes (see below for more information). Defaults to false.
|
-| `compute_updates` | | boolean | Whether to compute
pre/post update images (see below for more information). Defaults to false.
|
+| `net_changes` | | boolean | Whether to output
net changes (see below for more information). Defaults to false. It must be
false when `compute_updates` is true.
|
+| `compute_updates` | | boolean | Whether to compute
pre/post update images (see below for more information). Defaults to true if
`identifer_columns` are provided; otherwise, defaults to false.
|
| `identifier_columns` | | array<string> | The list of
identifier columns to compute updates. If the argument `compute_updates` is set
to true and `identifier_columns` are not provided, the table’s current
identifier fields will be used. |
Here is a list of commonly used Spark read options:
@@ -823,7 +823,10 @@ second snapshot deleted 1 record.
|2 | Bob |INSERT |0 |5390529835796506035|
|1 | Alice |DELETE |1 |8764748981452218370|
-Create a changelog view that computes net changes. It removes intermediate
changes and only outputs the net changes.
+#### Net Changes
+
+The procedure can remove intermediate changes across multiple snapshots, and
only outputs the net changes. Here is an example to create a changelog view
that computes net changes.
+
```sql
CALL spark_catalog.system.create_changelog_view(
table => 'db.tbl',
