add test and docs

docs/en/engines/table-engines/mergetree-family/annindexes.md

@@ -32,13 +32,18 @@ Approximate Nearest Neighbor Search Indexes (`ANNIndexes`) are similar to skip i
   LIMIT N
   ```
 
-In these queries, `DistanceFunction` is selected from [distance functions](../../../sql-reference/functions/distance-functions). `Point` is a known vector (something like `(0.1, 0.1, ... )`). `Value` - a float value that will bound the neighbourhood.
+In these queries, `DistanceFunction` is selected from [distance functions](../../../sql-reference/functions/distance-functions). `Point` is a known vector (something like `(0.1, 0.1, ... )`). To avoid writing large vectors, use [client parameters](../../../interfaces/cli.md#queries-with-parameters-cli-queries-with-parameters). `Value` - a float value that will bound the neighbourhood.
 
 !!! note "Note"
     ANN index can't speed up query that satisfies both types(`where + order by`, only one of them). All queries must have the limit, as algorithms are used to find nearest neighbors and need a specific number of them.
 
+!!! note "Note"
+    Indexes are applied only to queries with a limit less than the `max_limit_for_ann_queries` setting. This helps to avoid memory overflows in queries with a large limit. `max_limit_for_ann_queries` setting can be changed if you know you can provide enough memory. The default value is `1000000`.
+
 Both types of queries are handled the same way. The indexes get `n` neighbors (where `n` is taken from the `LIMIT` clause) and work with them. In `ORDER BY` query they remember the numbers of all parts of the granule that have at least one of neighbor. In `WHERE` query they remember only those parts that satisfy the requirements.
 
+
+
 ## Create table with ANNIndex
 
 ```sql

tests/queries/0_stateless/02354_annoy.reference

@@ -6,3 +6,11 @@
 1	[0,0,10]
 5	[0,0,10.2]
 4	[0,0,9.7]
+1	[0,0,10]
+2	[0,0,10.5]
+3	[0,0,9.5]
+4	[0,0,9.7]
+5	[0,0,10.2]
+1	[0,0,10]
+5	[0,0,10.2]
+4	[0,0,9.7]

tests/queries/0_stateless/02354_annoy.sql

@@ -24,6 +24,18 @@ FROM 02354_annoy
 ORDER BY L2Distance(embedding, [0.0, 0.0, 10.0])
 LIMIT 3;
 
+SET param_02354_target_vector='[0.0, 0.0, 10.0]';
+
+SELECT *
+FROM 02354_annoy
+WHERE L2Distance(embedding, {02354_target_vector: Array(Float32)}) < 1.0
+LIMIT 5;
+
+SELECT *
+FROM 02354_annoy
+ORDER BY L2Distance(embedding, {02354_target_vector: Array(Float32)})
+LIMIT 3;
+
 SELECT *
 FROM 02354_annoy
 ORDER BY L2Distance(embedding, [0.0, 0.0])