在日常数据库运维工作中，索引管理是性能调优的核心环节。无论是进行迁移评估、性能分析，还是健康检查，快速掌握用户或实例下所有表的索引分布情况都是首要任务。以下汇总了10个可直接复用的Oracle索引查询脚本，涵盖基本信息统计、无索引表发现、大表监控、索引使用分析等常见场景。每个脚本均附有说明注释，方便按需调整。

1. 查询当前用户下所有表的索引数量统计

SELECT     t.table_name,    COUNT(i.index_name) as index_count,    LISTAGG(i.index_name, ', ') WITHIN GROUP (ORDER BY i.index_name) as index_names
FROM user_tables t
LEFT JOIN user_indexes i ON t.table_name = i.table_name
GROUP BY t.table_name
ORDER BY COUNT(i.index_name) DESC, t.table_name;

2. 查询所有用户下所有表的索引数量（需DBA权限）

SELECT     i.table_owner,    i.table_name,    COUNT(i.index_name) as index_count,    LISTAGG(i.index_name, ', ') WITHIN GROUP (ORDER BY i.index_name) as index_names
FROM dba_indexes i
WHERE i.table_owner NOT IN ('SYS', 'SYSTEM', 'XDB', 'CTXSYS', 'MDSYS', 'ORDSYS')  -- 排除系统用户
GROUP BY i.table_owner, i.table_name
ORDER BY i.table_owner, COUNT(i.index_name) DESC, i.table_name;

3. 查询表及索引详细信息（适用于Oracle迁移至TiDB场景）——快速掌握待迁移生产表的行数、唯一索引等关键信息

SELECT     t.owner,    t.table_name,    t.num_rows as table_rows,    COUNT(i.index_name) as total_indexes,    SUM(CASE WHEN i.uniqueness = 'UNIQUE' THEN 1 ELSE 0 END) as unique_indexes,    SUM(CASE WHEN i.uniqueness = 'NONUNIQUE' THEN 1 ELSE 0 END) as nonunique_indexes,    SUM(CASE WHEN i.index_type = 'FUNCTION-BASED NORMAL' THEN 1 ELSE 0 END) as function_based_indexes
FROM dba_tables t
LEFT JOIN dba_indexes i ON t.owner = i.table_owner AND t.table_name = i.table_name
WHERE t.owner = 'YOUR_SCHEMA_NAME'  -- 替换为你的模式名
GROUP BY t.owner, t.table_name, t.num_rows
ORDER BY COUNT(i.index_name) DESC, t.table_name;

4. 按索引类型分组统计

SELECT     i.table_owner,    i.table_name,    i.index_type,    COUNT(*) as count_per_type,    LISTAGG(i.index_name, ', ') WITHIN GROUP (ORDER BY i.index_name) as index_list
FROM dba_indexes i
WHERE i.table_owner = 'YOUR_SCHEMA_NAME'  -- 替换为你的模式名
GROUP BY i.table_owner, i.table_name, i.index_type
ORDER BY i.table_name, i.index_type;

5. 查找没有索引的表（含当前用户与全部用户两种场景）

-- 查找当前用户下没有索引的表
SELECT     t.table_name,    t.num_rows,    t.blocks
FROM user_tables t
WHERE NOT EXISTS (
    SELECT 1 
    FROM user_indexes i 
    WHERE i.table_name = t.table_name
)
AND t.table_name NOT LIKE 'BIN$%'  -- 排除回收站中的表
ORDER BY t.num_rows DESC NULLS LAST;

-- 查找所有用户下没有索引的表（需要DBA权限）
SELECT     t.owner,    t.table_name,    t.num_rows
FROM dba_tables t
WHERE NOT EXISTS (
    SELECT 1 
    FROM dba_indexes i 
    WHERE i.table_owner = t.owner 
    AND i.table_name = t.table_name
)
AND t.owner NOT IN ('SYS', 'SYSTEM', 'XDB')
AND t.table_name NOT LIKE 'BIN$%'
ORDER BY t.owner, t.num_rows DESC NULLS LAST;

6. 统计每个索引包含的列数及明细

-- 统计每个索引的列数
SELECT     i.table_name,    i.index_name,    i.uniqueness,    i.status,    COUNT(ic.column_position) as column_count,    LISTAGG(ic.column_name, ', ') WITHIN GROUP (ORDER BY ic.column_position) as columns
FROM user_indexes i
JOIN user_ind_columns ic ON i.index_name = ic.index_name
GROUP BY i.table_name, i.index_name, i.uniqueness, i.status
ORDER BY i.table_name, i.index_name;

7. 实用的索引汇总查询：平均高度、叶子块及无效索引统计

-- 索引统计汇总
WITH index_stats AS (
    SELECT 
        owner,
        table_name,
        COUNT(*) as total_indexes,
        ROUND(A VG(blevel), 2) as a vg_blevel,
        ROUND(A VG(leaf_blocks), 2) as a vg_leaf_blocks,
        SUM(CASE WHEN status != 'VALID' THEN 1 ELSE 0 END) as invalid_indexes
    FROM dba_indexes
    WHERE owner = 'YOUR_SCHEMA_NAME'
    GROUP BY owner, table_name
)
SELECT 
    owner,
    COUNT(DISTINCT table_name) as tables_with_indexes,
    SUM(total_indexes) as total_index_count,
    ROUND(A VG(total_indexes), 2) as a vg_indexes_per_table,
    ROUND(MEDIAN(total_indexes), 2) as median_indexes_per_table,
    MAX(total_indexes) as max_indexes_in_table,
    SUM(invalid_indexes) as total_invalid_indexes
FROM index_stats
GROUP BY owner;

8. 生产环境监控：检测大表（行数超万）缺少索引的情况

-- 查找行数超过10000但索引数少于2个的表
SELECT     t.owner,    t.table_name,    t.num_rows,    COUNT(i.index_name) as index_count
FROM dba_tables t
LEFT JOIN dba_indexes i ON t.owner = i.table_owner AND t.table_name = i.table_name
WHERE t.num_rows > 10000
AND t.owner = 'YOUR_SCHEMA_NAME'
GROUP BY t.owner, t.table_name, t.num_rows
HA VING COUNT(i.index_name) < 2
ORDER BY t.num_rows DESC;

9. 查看索引使用情况（Oracle 11g+）——快速找出未使用的索引

SELECT     table_name,    index_name,    used
FROM v$object_usage
WHERE used = 'NO'  -- 查看未使用的索引
ORDER BY table_name;

10. 自动生成创建缺失索引的SQL脚本

SELECT     'CREATE INDEX idx_' || table_name || '_' || column_name || 
    ' ON ' || table_name || '(' || column_name || ');' as create_index_sql
FROM (
    SELECT DISTINCT
        t.table_name,
        tc.column_name
    FROM user_tables t
    JOIN user_tab_columns tc ON t.table_name = tc.table_name
    WHERE NOT EXISTS (
        SELECT 1 
        FROM user_ind_columns ic 
        WHERE ic.table_name = t.table_name 
        AND ic.column_name = tc.column_name
    )
    AND t.table_name NOT LIKE 'BIN$%'
    AND tc.column_name NOT LIKE '%ID'  -- 排除ID列
    AND tc.data_type IN ('VARCHAR2', 'CHAR', 'NUMBER', 'DATE')  -- 只对某些数据类型创建索引
)
WHERE ROWNUM <= 10;  -- 限制生成的数量