需要对 Oracle 中具有略微不同约束的类似查询执行进行粗略分组

Question

正在评估一些当前数据库计划停用的影响。与最近访问过受影响数据的用户进行单独通信是不可行的，因为数量。

我在想，如果我可以执行某种形式的模糊逻辑查找来按用户对查询进行分组，那么至少我可以识别由于预期约束更改而略有不同的重复查询。尽管远非完美，但这可以帮助表示运行定期查询以支持重复出现的业务功能与纯粹的临时查询。

任何人都可以提供一些可以让我开始的想法，或者让我知道是否有任何替代想法可以根据我的上述目标进行研究？

Answer 1

您可以结合使用 UTL_MATCH、DBA_HIST_SQLTEXT 和 DBA_HIST_SQLSTAT 来查找相似的查询执行。如果您没有获得 AWR 许可，或者只对最近的查询感兴趣，您可以使用 GV$SQLSTATS 而不是 DBA_HIST 表。

除了复杂之外，您还需要根据反复试验调整以下查询中的一些文字。目前，它只查看每个用户执行次数最多的前 10 个查询，并且只查找相似度得分大于或等于 60% 的前 5 个最相关的查询。

--Common queries and the top 5 most-closely related queries.
with statements as
(
    --All relevant SQL statements
    select
        sqlstats.parsing_schema_name,
        sqlstats.total_executions,
        sqltext.sql_id,
        --Convert CLOB to VARCHAR for UTL_MATCH.
        --Won't matter, since we're only interseted in fuzzy matches anyway.
        to_char(substr(sqltext.sql_text, 1, 1000)) sql_text,
        sqltext.command_type
    from
    (
        --All queries in AWR.
        select sql_id, sql_text, command_type
        from dba_hist_sqltext
    ) sqltext
    join
    (
        --Statistics for all queries in AWR.
        select sql_id, parsing_schema_name, sum(executions_delta) total_executions
        from dba_hist_sqlstat
        group by sql_id, parsing_schema_name
    ) sqlstats
        on sqltext.sql_id = sqlstats.sql_id
    order by parsing_schema_name, total_executions desc
)
--Top N most similar queries.
select *
from
(
    --Ranked similarity.
    select
        similarity.*,
        row_number() over (partition by sql_id1 order by similarity desc) top_similarity
    from
    (
        --Similarity between SQL statements for the Top N SQL and other SQL run by the same user.
        select
            top_n.parsing_schema_name, top_n.sql_id sql_id1, top_n.sql_text sql_text1, top_n.total_executions,
            statements.sql_id sql_id2, statements.sql_text sql_text2,
            utl_match.edit_distance_similarity(top_n.sql_text, statements.sql_text) similarity
        from
        (
            --Top N most executed queries.
            select *
            from
            (
                --Most executed queries per user.
                select
                    statements.*,
                    row_number () over (partition by parsing_schema_name order by total_executions desc) top_n 
                from statements
                order by parsing_schema_name, total_executions desc
            )
            where top_n <= 10
        ) top_n
        join statements
            on top_n.parsing_schema_name = statements.parsing_schema_name
            and top_n.command_type = statements.command_type
            and top_n.sql_id <> statements.sql_id
        order by top_n.sql_id, similarity desc, statements.sql_id
    ) similarity
) ranked_similarity
where top_similarity <= 5
    and similarity >= 60
order by parsing_schema_name, sql_id1, top_similarity;

需要对 Oracle 中具有略微不同约束的类似查询执行进行粗略分组

Need to roughly group similar query executions in Oracle that have slightly different constraints

oracle

fuzzy-search

fuzzy-logic

fuzzy