EXPRESSION clause is ignored for KEY columns in CREATE DICTIONARY #15156
Description
Tested on 20.9.2
I want to create a dictionary for a CH table without a UInt64 key.
It seems that the EXPRESSION clause is being completely ignored:
CREATE DICTIONARY test.query_log
(
`query_key` UInt64 EXPRESSION cityHash64(query_id),
`query_id` String,
`query_duration_ms` UInt64
)
PRIMARY KEY query_key
SOURCE(CLICKHOUSE(HOST 'localhost' PORT 9000 USER 'default' PASSWORD '' DB 'system' TABLE 'query_log' WHERE 'type>1'))
LAYOUT(DIRECT())
Ok.
SELECT *
FROM test.query_log
LIMIT 3
Received exception from server (version 20.9.2):
Code: 47. DB::Exception: Received from localhost:9000. DB::Exception: Missing columns: 'query_key' while processing query: 'SELECT query_key, query_id, event_date, event_time, query_start_time, query_duration_ms, read_rows, read_bytes, written_rows, written_bytes, result_rows, result_bytes, memory_usage FROM system.query_log WHERE type > 1', required columns: 'query_key' 'query_id' 'written_rows' 'query_start_time' 'query_duration_ms' 'read_rows' 'read_bytes' 'event_time' 'written_bytes' 'event_date' 'memory_usage' 'type' 'result_rows' 'result_bytes', source columns: 'Settings.Values' 'Settings.Names' 'ProfileEvents.Values' 'revision' 'quota_key' 'http_user_agent' 'client_version_minor' 'client_revision' 'client_hostname' 'os_user' 'interface' 'client_name' 'initial_address' 'initial_user' 'address' 'query_id' 'client_version_patch' 'user' 'ProfileEvents.Names' 'client_version_major' 'is_initial_query' 'port' 'initial_query_id' 'stack_trace' 'result_bytes' 'type' 'written_bytes' 'result_rows' 'event_time' 'http_method' 'written_rows' 'exception_code' 'query' 'current_database' 'read_bytes' 'exception' 'initial_port' 'read_rows' 'query_duration_ms' 'thread_ids' 'query_start_time' 'memory_usage' 'event_date'.
An XML dictionary works, although I don't understand where the row with the empty query_id comes from.
<yandex>
<dictionary>
<name>query_log</name>
<source>
<clickhouse>
<host>localhost</host>
<port>9000</port>
<user>default</user>
<password></password>
<db>system</db>
<table>query_log</table>
<where>type>1</where>
</clickhouse>
</source>
<layout>
<direct />
</layout>
<structure>
<id>
<name>query_key</name>
<expression>cityHash64(query_id)</expression>
</id>
<attribute>
<name>query_id</name>
<type>String</type>
<null_value></null_value>
</attribute>
<attribute>
<name>query_duration_ms</name>
<type>UInt64</type>
<null_value>0</null_value>
</attribute>
</structure>
</dictionary>
</yandex>
SELECT *
FROM dict.query_log
LIMIT 3
┌─query_key─┬─query_id─┬─query_duration_ms─┐
│ 0 │ │ 0 │
└───────────┴──────────┴───────────────────┘
┌────────────query_key─┬─query_id─────────────────────────────┬─query_duration_ms─┐
│ 13232500466751825811 │ 5b9f6640-f0ec-4045-93d3-3fc9929f338f │ 8 │
│ 10671327996374602370 │ 37f41e52-9158-4f9d-b011-23a18c4121e6 │ 6 │
│ 7431129089585880466 │ 7c6eb4ee-6aaa-4b6a-9095-7a97514aba97 │ 636 │
└──────────────────────┴──────────────────────────────────────┴───────────────────┘
4 rows in set. Elapsed: 0.025 sec. Processed 84.58 thousand rows, 4.57 MB (3.37 million rows/s., 182.23 MB/s.)