# Instructions
ClickHouse native Where clause syntax used in the log query criteria filter section.
Official documents (opens new window)
# Use cases after migration from Alibaba cloud
For example,we used to use Alibaba cloud's fuzzy matching to search.The following statement will perform fuzzy matching on these two conditions.
Electron and docs_text_copy
So how to use it in ClickVisual? By default(establish a complete set of data collection process through clickVisual),use the following statement instead.
_raw_log_ like '%Electron%' and _raw_log_ like '%docs_text_copy%'
However, this performance is not very good,you can add Analysis fields to improve query efficiency. Suppose that the target field we match is in a nested JSON: browserName and code field in body as shown below
If you see the following config in Analysis panel on the left,you can directly use the following statement to query.
body.browserName='browserName' and body.code='docs_text_copy'
If there is no any Analysis field,you need to configure.
After configuration, the query statement is:
body.browserName='browserName' and body.code='docs_text_copy'
If the query is still slow in this case,you can configure that:set siphash and urlhash(truncate parameters after '?'and hash).By establishing hash mapping, query efficiency is improved.
The query statement is still:
body.browserName='browserName' and body.code='docs_text_copy'