AP加速引擎（rds_duckdb）_云数据库 RDS(RDS)-阿里云帮助中心

当您进行复杂查询并期望快速获得查询结果时，可以利用云数据库RDS PostgreSQL的AP加速引擎（rds_duckdb）。该引擎提供了列存表和向量化执行能力，显著提升复杂查询的执行速度，且无需修改原始查询语句，从而确保您能够方便且高效地获取结果。

重要

AP加速引擎（rds_duckdb）当前白名单开放中，如需使用，请联系我们。

功能简介

rds_duckdb在RDS PostgreSQL中引入了高效、资源友好的DuckDB，以增强分析型查询能力。该插件可以将RDS PostgreSQL中的本地表导出为列存表，并启用分析型查询加速（Analytical Processing Query Acceleration，简称AP）功能，显著提升了复杂查询的执行速度，从而更好地满足分析型业务的需求。

前提条件

实例大版本为RDS PostgreSQL 16。
实例内核小版本为20240830及以上。
已将shared_preload_libraries参数取值设置为'rds_duckdb'，配置参数的详情操作请参见设置实例参数。

注意事项

暂不支持RDS PostgreSQL主备之间同步导出的列存表数据，
暂不支持导出列存表数据进行自动增量同步。

创建和删除插件

使用高权限账户进行插件的创建与删除操作。

创建插件

CREATE EXTENSION rds_duckdb;

删除插件

DROP EXTENSION rds_duckdb;

管理列存表

创建列存表

使用以下命令，将RDS PostgreSQL本地表（用户表、物化视图、外表等）导出为一份列存表，该列存表将用于加速分析型查询。

SELECT rds_duckdb.create_duckdb_table('本地表名称');

刷新列存表

使用以下命令，依据RDS PostgreSQL本地表的最新数据刷新导出的列存表，同时更新表结构信息和数据内容。

SELECT rds_duckdb.refresh_duckdb_table('本地表名称');

删除列存表

SELECT rds_duckdb.drop_duckdb_table('本地表名称');

管理AP加速

rds_duckdb目前支持加速只读查询。开启AP加速后，当SQL类型为查询且涉及的表均有对应的DuckDB列存表时，SQL将由DuckDB执行以实现加速。如果SQL属于暂不支持的DML、DDL操作或包含不存在的列存表，则将回退到RDS PostgreSQL中执行。

对于回退到RDS PostgreSQL执行的SQL，系统会给出警告提示，格式为：WARNING: Trying to execute an operation with non-duckdb tables(test), fallback to PG。其中，括号内显示的是不包含对应DuckDB列存表的RDS PostgreSQL表。

非只读的SQL查询也会收到提示，显示为：WARNING: Modification operations on DuckDB tables are currently not supported, fallback to PG。

开启AP加速

SET rds_duckdb.execution = on;

设置AP加速参数

您可以在会话中通过调整参数配置来实现对AP加速性能的控制。例如：

SET rds_duckdb.worker_threads = 32;
SET rds_duckdb.memory_limit = 16384;

参数名称

参数说明

取值建议

rds_duckdb.worker_threads

AP加速时使用的工作线程数量。

取值范围：1~255。

默认值：1，表示只有一个工作线程。

建议希望实现显著性能提升的用户，将该值设置为CPU核心数。
该参数与执行机器的硬件密切相关，值越大，执行AP加速时CPU的负载越高。因此，需要根据实际情况合理设置该参数。
该参数设置较高时，可以获得更优异的性能，然而CPU负载也会相应增加；反之，若该参数设置较低，则加速效果将会有所降低，但系统CPU负载也会随之减少。

rds_duckdb.memory_limit

AP加速时使用的内存限制。

单位：MB（配置参数时无需添加单位）。

取值范围：1~INT32_MAX。

默认值：100，表示上限为100 MB。

建议希望实现显著性能提升的用户，将该值设置为尽可能大的数值。
该参数与执行机器的硬件密切相关，值越大，执行AP加速时内存的使用量越高。因此，需要根据实际情况合理设置该参数。
默认参数值设置较为保守，建议用户根据设备的实际情况进行相应调整。
该值过小时可能会影响大表导出列存表的过程，并影响AP加速的性能。

说明

DuckDB的参数请参见DuckDB。

关闭AP加速

SET rds_duckdb.execution = off;

使用示例

rds_duckdb性能测试

本文以Linux环境为例，使用标准TPC-H测试评估rds_duckdb对复杂查询的性能提升情况。

创建ECS实例并构建测试数据。
1. 通过PostgreSQL官方网站下载并安装PostgreSQL。
2. 下载dbgen工具。
```
wget https://github.com/electrum/tpch-dbgen/archive/refs/heads/master.zip
yum install -y unzip zip
unzip master.zip
cd tpch-dbgen-master/
echo "#define EOL_HANDLING 1" >> config.h # 消除生成数据末尾的'|'
make
./dbgen --help
```
3. 生成测试数据。
  本文以测试数据存储路径为/data/test，测试数据为100 GB为例。您可根据自身需求选择数据路径和适当的数据集大小。
```
./dbgen -s 100
mkdir /data/test/tpch_data
mv *.tbl /data/test/tpch_data
```
  说明
  数据量的大小对查询速度具有直接影响。TPC-H中使用SF来描述数据量，其中1 SF对应1 GB。以此类推，100 SF即为100 GB。需要注意的是，1 SF对应的数据量仅包括8个表的总数据量，不包含索引等其他空间占用。因此，在准备数据时，应预留更多的存储空间。

按照前提条件创建RDS PostgreSQL数据库，并导入相关测试数据。

创建RDS PostgreSQL实例。
创建高权限账号。
连接PostgreSQL实例。

执行如下语句，创建8张TPC-H测试表。

CREATE TABLE customer(c_custkey BIGINT NOT NULL, c_name VARCHAR NOT NULL, c_address VARCHAR NOT NULL, c_nationkey INTEGER NOT NULL, c_phone VARCHAR NOT NULL, c_acctbal DECIMAL(15,2) NOT NULL, c_mktsegment VARCHAR NOT NULL, c_comment VARCHAR NOT NULL);
CREATE TABLE lineitem(l_orderkey BIGINT NOT NULL, l_partkey BIGINT NOT NULL, l_suppkey BIGINT NOT NULL, l_linenumber BIGINT NOT NULL, l_quantity DECIMAL(15,2) NOT NULL, l_extendedprice DECIMAL(15,2) NOT NULL, l_discount DECIMAL(15,2) NOT NULL, l_tax DECIMAL(15,2) NOT NULL, l_returnflag VARCHAR NOT NULL, l_linestatus VARCHAR NOT NULL, l_shipdate DATE NOT NULL, l_commitdate DATE NOT NULL, l_receiptdate DATE NOT NULL, l_shipinstruct VARCHAR NOT NULL, l_shipmode VARCHAR NOT NULL, l_comment VARCHAR NOT NULL);
CREATE TABLE nation(n_nationkey INTEGER NOT NULL, n_name VARCHAR NOT NULL, n_regionkey INTEGER NOT NULL, n_comment VARCHAR NOT NULL);
CREATE TABLE orders(o_orderkey BIGINT NOT NULL, o_custkey BIGINT NOT NULL, o_orderstatus VARCHAR NOT NULL, o_totalprice DECIMAL(15,2) NOT NULL, o_orderdate DATE NOT NULL, o_orderpriority VARCHAR NOT NULL, o_clerk VARCHAR NOT NULL, o_shippriority INTEGER NOT NULL, o_comment VARCHAR NOT NULL);
CREATE TABLE part(p_partkey BIGINT NOT NULL, p_name VARCHAR NOT NULL, p_mfgr VARCHAR NOT NULL, p_brand VARCHAR NOT NULL, p_type VARCHAR NOT NULL, p_size INTEGER NOT NULL, p_container VARCHAR NOT NULL, p_retailprice DECIMAL(15,2) NOT NULL, p_comment VARCHAR NOT NULL);
CREATE TABLE partsupp(ps_partkey BIGINT NOT NULL, ps_suppkey BIGINT NOT NULL, ps_availqty BIGINT NOT NULL, ps_supplycost DECIMAL(15,2) NOT NULL, ps_comment VARCHAR NOT NULL);
CREATE TABLE region(r_regionkey INTEGER NOT NULL, r_name VARCHAR NOT NULL, r_comment VARCHAR NOT NULL);
CREATE TABLE supplier(s_suppkey BIGINT NOT NULL, s_name VARCHAR NOT NULL, s_address VARCHAR NOT NULL, s_nationkey INTEGER NOT NULL, s_phone VARCHAR NOT NULL, s_acctbal DECIMAL(15,2) NOT NULL, s_comment VARCHAR NOT NULL);

\dt # 查看导入的数据表

导入已生成的测试数据。

COPY customer FROM '/data/test/tpch_data/customer.tbl' DELIMITER '|';
COPY lineitem FROM '/data/test/tpch_data/lineitem.tbl' DELIMITER '|';
COPY nation FROM '/data/test/tpch_data/nation.tbl' DELIMITER '|';
COPY orders FROM '/data/test/tpch_data/orders.tbl' DELIMITER '|';
COPY part FROM '/data/test/tpch_data/part.tbl' DELIMITER '|';
COPY partsupp FROM '/data/test/tpch_data/partsupp.tbl' DELIMITER '|';
COPY region FROM '/data/test/tpch_data/region.tbl' DELIMITER '|';
COPY supplier FROM '/data/test/tpch_data/supplier.tbl' DELIMITER '|';

\dt+ # 查看导入的数据表的详细信息

安装rds_duckdb插件并生成列存表。

安装rds_duckdb插件。
```
CREATE EXTENSION rds_duckdb;
```

生成列存表。

# 将PG本地表转换生成对应的列存表
SELECT rds_duckdb.create_duckdb_table('customer');
SELECT rds_duckdb.create_duckdb_table('lineitem');
SELECT rds_duckdb.create_duckdb_table('nation');
SELECT rds_duckdb.create_duckdb_table('orders');
SELECT rds_duckdb.create_duckdb_table('part');
SELECT rds_duckdb.create_duckdb_table('partsupp');
SELECT rds_duckdb.create_duckdb_table('region');
SELECT rds_duckdb.create_duckdb_table('supplier');

设置AP加速参数。

# 根据您自己的测试机情况设置线程数和内存限制（单位为MB）
SET rds_duckdb.worker_threads = 32;
SET rds_duckdb.memory_limit = 8192;

开启AP加速。

SET rds_duckdb.execution = on;

# 开启计时
\timing on

# 将结果重定向到文件中
\o /data/test/tpch_data/tpch_out

执行如下22条TPC-H标准测试SQL，并测试查询性能。

标准测试SQL

-- Q1
SELECT
    l_returnflag,
    l_linestatus,
    sum(l_quantity) AS sum_qty,
    sum(l_extendedprice) AS sum_base_price,
    sum(l_extendedprice * (1 - l_discount)) AS sum_disc_price,
    sum(l_extendedprice * (1 - l_discount) * (1 + l_tax)) AS sum_charge,
    avg(l_quantity) AS avg_qty,
    avg(l_extendedprice) AS avg_price,
    avg(l_discount) AS avg_disc,
    count(*) AS count_order
FROM
    lineitem
WHERE
    l_shipdate <= CAST('1998-09-02' AS date)
GROUP BY
    l_returnflag,
    l_linestatus
ORDER BY
    l_returnflag,
    l_linestatus;


-- Q2
SELECT
    s_acctbal,
    s_name,
    n_name,
    p_partkey,
    p_mfgr,
    s_address,
    s_phone,
    s_comment
FROM
    part,
    supplier,
    partsupp,
    nation,
    region
WHERE
    p_partkey = ps_partkey
    AND s_suppkey = ps_suppkey
    AND p_size = 15
    AND p_type LIKE '%BRASS'
    AND s_nationkey = n_nationkey
    AND n_regionkey = r_regionkey
    AND r_name = 'EUROPE'
    AND ps_supplycost = (
        SELECT
            min(ps_supplycost)
        FROM
            partsupp,
            supplier,
            nation,
            region
        WHERE
            p_partkey = ps_partkey
            AND s_suppkey = ps_suppkey
            AND s_nationkey = n_nationkey
            AND n_regionkey = r_regionkey
            AND r_name = 'EUROPE')
ORDER BY
    s_acctbal DESC,
    n_name,
    s_name,
    p_partkey
LIMIT 100;


-- Q3
SELECT
    l_orderkey,
    sum(l_extendedprice * (1 - l_discount)) AS revenue,
    o_orderdate,
    o_shippriority
FROM
    customer,
    orders,
    lineitem
WHERE
    c_mktsegment = 'BUILDING'
    AND c_custkey = o_custkey
    AND l_orderkey = o_orderkey
    AND o_orderdate < CAST('1995-03-15' AS date)
    AND l_shipdate > CAST('1995-03-15' AS date)
GROUP BY
    l_orderkey,
    o_orderdate,
    o_shippriority
ORDER BY
    revenue DESC,
    o_orderdate
LIMIT 10;


-- Q4
SELECT
    o_orderpriority,
    count(*) AS order_count
FROM
    orders
WHERE
    o_orderdate >= CAST('1993-07-01' AS date)
    AND o_orderdate < CAST('1993-10-01' AS date)
    AND EXISTS (
        SELECT
            *
        FROM
            lineitem
        WHERE
            l_orderkey = o_orderkey
            AND l_commitdate < l_receiptdate)
GROUP BY
    o_orderpriority
ORDER BY
    o_orderpriority;


-- Q5
SELECT
    n_name,
    sum(l_extendedprice * (1 - l_discount)) AS revenue
FROM
    customer,
    orders,
    lineitem,
    supplier,
    nation,
    region
WHERE
    c_custkey = o_custkey
    AND l_orderkey = o_orderkey
    AND l_suppkey = s_suppkey
    AND c_nationkey = s_nationkey
    AND s_nationkey = n_nationkey
    AND n_regionkey = r_regionkey
    AND r_name = 'ASIA'
    AND o_orderdate >= CAST('1994-01-01' AS date)
    AND o_orderdate < CAST('1995-01-01' AS date)
GROUP BY
    n_name
ORDER BY
    revenue DESC;


-- Q6
SELECT
    sum(l_extendedprice * l_discount) AS revenue
FROM
    lineitem
WHERE
    l_shipdate >= CAST('1994-01-01' AS date)
    AND l_shipdate < CAST('1995-01-01' AS date)
    AND l_discount BETWEEN 0.05
    AND 0.07
    AND l_quantity < 24;


-- Q7
SELECT
    supp_nation,
    cust_nation,
    l_year,
    sum(volume) AS revenue
FROM (
    SELECT
        n1.n_name AS supp_nation,
        n2.n_name AS cust_nation,
        extract(year FROM l_shipdate) AS l_year,
        l_extendedprice * (1 - l_discount) AS volume
    FROM
        supplier,
        lineitem,
        orders,
        customer,
        nation n1,
        nation n2
    WHERE
        s_suppkey = l_suppkey
        AND o_orderkey = l_orderkey
        AND c_custkey = o_custkey
        AND s_nationkey = n1.n_nationkey
        AND c_nationkey = n2.n_nationkey
        AND ((n1.n_name = 'FRANCE'
                AND n2.n_name = 'GERMANY')
            OR (n1.n_name = 'GERMANY'
                AND n2.n_name = 'FRANCE'))
        AND l_shipdate BETWEEN CAST('1995-01-01' AS date)
        AND CAST('1996-12-31' AS date)) AS shipping
GROUP BY
    supp_nation,
    cust_nation,
    l_year
ORDER BY
    supp_nation,
    cust_nation,
    l_year;


-- Q8
SELECT
    o_year,
    sum(
        CASE WHEN nation = 'BRAZIL' THEN
            volume
        ELSE
            0
        END) / sum(volume) AS mkt_share
FROM (
    SELECT
        extract(year FROM o_orderdate) AS o_year,
        l_extendedprice * (1 - l_discount) AS volume,
        n2.n_name AS nation
    FROM
        part,
        supplier,
        lineitem,
        orders,
        customer,
        nation n1,
        nation n2,
        region
    WHERE
        p_partkey = l_partkey
        AND s_suppkey = l_suppkey
        AND l_orderkey = o_orderkey
        AND o_custkey = c_custkey
        AND c_nationkey = n1.n_nationkey
        AND n1.n_regionkey = r_regionkey
        AND r_name = 'AMERICA'
        AND s_nationkey = n2.n_nationkey
        AND o_orderdate BETWEEN CAST('1995-01-01' AS date)
        AND CAST('1996-12-31' AS date)
        AND p_type = 'ECONOMY ANODIZED STEEL') AS all_nations
GROUP BY
    o_year
ORDER BY
    o_year;


-- Q9
SELECT
    nation,
    o_year,
    sum(amount) AS sum_profit
FROM (
    SELECT
        n_name AS nation,
        extract(year FROM o_orderdate) AS o_year,
        l_extendedprice * (1 - l_discount) - ps_supplycost * l_quantity AS amount
    FROM
        part,
        supplier,
        lineitem,
        partsupp,
        orders,
        nation
    WHERE
        s_suppkey = l_suppkey
        AND ps_suppkey = l_suppkey
        AND ps_partkey = l_partkey
        AND p_partkey = l_partkey
        AND o_orderkey = l_orderkey
        AND s_nationkey = n_nationkey
        AND p_name LIKE '%green%') AS profit
GROUP BY
    nation,
    o_year
ORDER BY
    nation,
    o_year DESC;


-- Q10
SELECT
    c_custkey,
    c_name,
    sum(l_extendedprice * (1 - l_discount)) AS revenue,
    c_acctbal,
    n_name,
    c_address,
    c_phone,
    c_comment
FROM
    customer,
    orders,
    lineitem,
    nation
WHERE
    c_custkey = o_custkey
    AND l_orderkey = o_orderkey
    AND o_orderdate >= CAST('1993-10-01' AS date)
    AND o_orderdate < CAST('1994-01-01' AS date)
    AND l_returnflag = 'R'
    AND c_nationkey = n_nationkey
GROUP BY
    c_custkey,
    c_name,
    c_acctbal,
    c_phone,
    n_name,
    c_address,
    c_comment
ORDER BY
    revenue DESC
LIMIT 20;


-- Q11
SELECT
    ps_partkey,
    sum(ps_supplycost * ps_availqty) AS value
FROM
    partsupp,
    supplier,
    nation
WHERE
    ps_suppkey = s_suppkey
    AND s_nationkey = n_nationkey
    AND n_name = 'GERMANY'
GROUP BY
    ps_partkey
HAVING
    sum(ps_supplycost * ps_availqty) > (
        SELECT
            sum(ps_supplycost * ps_availqty) * 0.0001000000
        FROM
            partsupp,
            supplier,
            nation
        WHERE
            ps_suppkey = s_suppkey
            AND s_nationkey = n_nationkey
            AND n_name = 'GERMANY')
ORDER BY
    value DESC;


-- Q12
SELECT
    l_shipmode,
    sum(
        CASE WHEN o_orderpriority = '1-URGENT'
            OR o_orderpriority = '2-HIGH' THEN
            1
        ELSE
            0
        END) AS high_line_count,
    sum(
        CASE WHEN o_orderpriority <> '1-URGENT'
            AND o_orderpriority <> '2-HIGH' THEN
            1
        ELSE
            0
        END) AS low_line_count
FROM
    orders,
    lineitem
WHERE
    o_orderkey = l_orderkey
    AND l_shipmode IN ('MAIL', 'SHIP')
    AND l_commitdate < l_receiptdate
    AND l_shipdate < l_commitdate
    AND l_receiptdate >= CAST('1994-01-01' AS date)
    AND l_receiptdate < CAST('1995-01-01' AS date)
GROUP BY
    l_shipmode
ORDER BY
    l_shipmode;


-- Q13
SELECT
    c_count,
    count(*) AS custdist
FROM (
    SELECT
        c_custkey,
        count(o_orderkey)
    FROM
        customer
    LEFT OUTER JOIN orders ON c_custkey = o_custkey
    AND o_comment NOT LIKE '%special%requests%'
GROUP BY
    c_custkey) AS c_orders (c_custkey,
        c_count)
GROUP BY
    c_count
ORDER BY
    custdist DESC,
    c_count DESC;


-- Q14
SELECT
    100.00 * sum(
        CASE WHEN p_type LIKE 'PROMO%' THEN
            l_extendedprice * (1 - l_discount)
        ELSE
            0
        END) / sum(l_extendedprice * (1 - l_discount)) AS promo_revenue
FROM
    lineitem,
    part
WHERE
    l_partkey = p_partkey
    AND l_shipdate >= date '1995-09-01'
    AND l_shipdate < CAST('1995-10-01' AS date);


-- Q15
SELECT
    s_suppkey,
    s_name,
    s_address,
    s_phone,
    total_revenue
FROM
    supplier,
    (
        SELECT
            l_suppkey AS supplier_no,
            sum(l_extendedprice * (1 - l_discount)) AS total_revenue
        FROM
            lineitem
        WHERE
            l_shipdate >= CAST('1996-01-01' AS date)
            AND l_shipdate < CAST('1996-04-01' AS date)
        GROUP BY
            supplier_no) revenue0
WHERE
    s_suppkey = supplier_no
    AND total_revenue = (
        SELECT
            max(total_revenue)
        FROM (
            SELECT
                l_suppkey AS supplier_no,
                sum(l_extendedprice * (1 - l_discount)) AS total_revenue
            FROM
                lineitem
            WHERE
                l_shipdate >= CAST('1996-01-01' AS date)
                AND l_shipdate < CAST('1996-04-01' AS date)
            GROUP BY
                supplier_no) revenue1)
ORDER BY
    s_suppkey;


-- Q16
SELECT
    p_brand,
    p_type,
    p_size,
    count(DISTINCT ps_suppkey) AS supplier_cnt
FROM
    partsupp,
    part
WHERE
    p_partkey = ps_partkey
    AND p_brand <> 'Brand#45'
    AND p_type NOT LIKE 'MEDIUM POLISHED%'
    AND p_size IN (49, 14, 23, 45, 19, 3, 36, 9)
    AND ps_suppkey NOT IN (
        SELECT
            s_suppkey
        FROM
            supplier
        WHERE
            s_comment LIKE '%Customer%Complaints%')
GROUP BY
    p_brand,
    p_type,
    p_size
ORDER BY
    supplier_cnt DESC,
    p_brand,
    p_type,
    p_size;


-- Q17
SELECT
    sum(l_extendedprice) / 7.0 AS avg_yearly
FROM
    lineitem,
    part
WHERE
    p_partkey = l_partkey
    AND p_brand = 'Brand#23'
    AND p_container = 'MED BOX'
    AND l_quantity < (
        SELECT
            0.2 * avg(l_quantity)
        FROM
            lineitem
        WHERE
            l_partkey = p_partkey);


-- Q18
SELECT
    c_name,
    c_custkey,
    o_orderkey,
    o_orderdate,
    o_totalprice,
    sum(l_quantity)
FROM
    customer,
    orders,
    lineitem
WHERE
    o_orderkey IN (
        SELECT
            l_orderkey
        FROM
            lineitem
        GROUP BY
            l_orderkey
        HAVING
            sum(l_quantity) > 300)
    AND c_custkey = o_custkey
    AND o_orderkey = l_orderkey
GROUP BY
    c_name,
    c_custkey,
    o_orderkey,
    o_orderdate,
    o_totalprice
ORDER BY
    o_totalprice DESC,
    o_orderdate
LIMIT 100;


-- Q19
SELECT
    sum(l_extendedprice * (1 - l_discount)) AS revenue
FROM
    lineitem,
    part
WHERE (p_partkey = l_partkey
    AND p_brand = 'Brand#12'
    AND p_container IN ('SM CASE', 'SM BOX', 'SM PACK', 'SM PKG')
    AND l_quantity >= 1
    AND l_quantity <= 1 + 10
    AND p_size BETWEEN 1 AND 5
    AND l_shipmode IN ('AIR', 'AIR REG')
    AND l_shipinstruct = 'DELIVER IN PERSON')
    OR (p_partkey = l_partkey
        AND p_brand = 'Brand#23'
        AND p_container IN ('MED BAG', 'MED BOX', 'MED PKG', 'MED PACK')
        AND l_quantity >= 10
        AND l_quantity <= 10 + 10
        AND p_size BETWEEN 1 AND 10
        AND l_shipmode IN ('AIR', 'AIR REG')
        AND l_shipinstruct = 'DELIVER IN PERSON')
    OR (p_partkey = l_partkey
        AND p_brand = 'Brand#34'
        AND p_container IN ('LG CASE', 'LG BOX', 'LG PACK', 'LG PKG')
        AND l_quantity >= 20
        AND l_quantity <= 20 + 10
        AND p_size BETWEEN 1 AND 15
        AND l_shipmode IN ('AIR', 'AIR REG')
        AND l_shipinstruct = 'DELIVER IN PERSON');


-- Q20
SELECT
    s_name,
    s_address
FROM
    supplier,
    nation
WHERE
    s_suppkey IN (
        SELECT
            ps_suppkey
        FROM
            partsupp
        WHERE
            ps_partkey IN (
                SELECT
                    p_partkey
                FROM
                    part
                WHERE
                    p_name LIKE 'forest%')
                AND ps_availqty > (
                    SELECT
                        0.5 * sum(l_quantity)
                    FROM
                        lineitem
                    WHERE
                        l_partkey = ps_partkey
                        AND l_suppkey = ps_suppkey
                        AND l_shipdate >= CAST('1994-01-01' AS date)
                        AND l_shipdate < CAST('1995-01-01' AS date)))
            AND s_nationkey = n_nationkey
            AND n_name = 'CANADA'
        ORDER BY
            s_name;


-- Q21
SELECT
    s_name,
    count(*) AS numwait
FROM
    supplier,
    lineitem l1,
    orders,
    nation
WHERE
    s_suppkey = l1.l_suppkey
    AND o_orderkey = l1.l_orderkey
    AND o_orderstatus = 'F'
    AND l1.l_receiptdate > l1.l_commitdate
    AND EXISTS (
        SELECT
            *
        FROM
            lineitem l2
        WHERE
            l2.l_orderkey = l1.l_orderkey
            AND l2.l_suppkey <> l1.l_suppkey)
    AND NOT EXISTS (
        SELECT
            *
        FROM
            lineitem l3
        WHERE
            l3.l_orderkey = l1.l_orderkey
            AND l3.l_suppkey <> l1.l_suppkey
            AND l3.l_receiptdate > l3.l_commitdate)
    AND s_nationkey = n_nationkey
    AND n_name = 'SAUDI ARABIA'
GROUP BY
    s_name
ORDER BY
    numwait DESC,
    s_name
LIMIT 100;


-- Q22
SELECT
    cntrycode,
    count(*) AS numcust,
    sum(c_acctbal) AS totacctbal
FROM (
    SELECT
        substring(c_phone FROM 1 FOR 2) AS cntrycode,
        c_acctbal
    FROM
        customer
    WHERE
        substring(c_phone FROM 1 FOR 2) IN ('13', '31', '23', '29', '30', '18', '17')
        AND c_acctbal > (
            SELECT
                avg(c_acctbal)
            FROM
                customer
            WHERE
                c_acctbal > 0.00
                AND substring(c_phone FROM 1 FOR 2) IN ('13', '31', '23', '29', '30', '18', '17'))
            AND NOT EXISTS (
                SELECT
                    *
                FROM
                    orders
                WHERE
                    o_custkey = c_custkey)) AS custsale
GROUP BY
    cntrycode
ORDER BY
    cntrycode;

查看SQL执行计划

使用EXPLAIN语句查看开启和关闭AP加速后，SQL语句的执行计划。例如：

开启AP加速后，SQL语句的执行计划如下。

开启AP加速

tpch_10x=# SET rds_duckdb.execution = on;
SET
tpch_10x=# EXPLAIN SELECT
tpch_10x-#     100.00 * sum(
tpch_10x(#         CASE WHEN p_type LIKE 'PROMO%' THEN
tpch_10x(#             l_extendedprice * (1 - l_discount)
tpch_10x(#         ELSE
tpch_10x(#             0
tpch_10x(#         END) / sum(l_extendedprice * (1 - l_discount)) AS promo_revenue
tpch_10x-# FROM
tpch_10x-#     lineitem,
tpch_10x-#     part
tpch_10x-# WHERE
tpch_10x-#     l_partkey = p_partkey
tpch_10x-#     AND l_shipdate >= date '1995-09-01'
tpch_10x-#     AND l_shipdate < CAST('1995-10-01' AS date);
                         QUERY PLAN
------------------------------------------------------------
 Custom Scan (DuckDBNode)  (cost=0.00..0.00 rows=0 width=0)
   DuckDB Plan:

 ┌───────────────────────────┐
 │         PROJECTION        │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
 │        Projections:       │
 │       promo_revenue       │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
 │   Estimated Cardinality:  │
 │             1             │
 └─────────────┬─────────────┘
 ┌─────────────┴─────────────┐
 │    UNGROUPED_AGGREGATE    │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
 │        Aggregates:        │
 │          sum(#0)          │
 │          sum(#1)          │
 └─────────────┬─────────────┘
 ┌─────────────┴─────────────┐
 │         PROJECTION        │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
 │        Projections:       │
 │ CASE  WHEN (prefix(p_type,│
 │    'PROMO')) THEN (CAST(  │
 │ (l_extendedprice * (1.000 │
 │    - CAST(l_discount AS   │
 │     DECIMAL(18,3)))) AS   │
 │   DECIMAL(20,5))) ELSE 0  │
 │         .00000 END        │
 │ (l_extendedprice * (1.000 │
 │    - CAST(l_discount AS   │
 │      DECIMAL(18,3))))     │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
 │   Estimated Cardinality:  │
 │          6600339          │
 └─────────────┬─────────────┘
 ┌─────────────┴─────────────┐
 │         HASH_JOIN         │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
 │         Join Type:        │
 │           INNER           │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
 │        Conditions:        ├──────────────┐
 │   l_partkey = p_partkey   │              │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │              │
 │   Estimated Cardinality:  │              │
 │          6600339          │              │
 └─────────────┬─────────────┘              │
 ┌─────────────┴─────────────┐┌─────────────┴─────────────┐
 │         SEQ_SCAN          ││         SEQ_SCAN          │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   ││   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
 │        Stringified:       ││        Stringified:       │
 │          lineitem         ││            part           │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   ││   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
 │        Projections:       ││        Projections:       │
 │         l_partkey         ││         p_partkey         │
 │      l_extendedprice      ││           p_type          │
 │         l_discount        ││   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   ││   Estimated Cardinality:  │
 │          Filters:         ││          2000000          │
 │ l_shipdate>='1995-09-01': ││                           │
 │ :DATE AND l_shipdate<'1995││                           │
 │     -10-01'::DATE AND     ││                           │
 │   l_shipdate IS NOT NULL  ││                           │
 │   ─ ─ ─ ─ ─ ─ ─ ─ ─ ─ ─   ││                           │
 │   Estimated Cardinality:  ││                           │
 │          11997210         ││                           │
 └───────────────────────────┘└───────────────────────────┘


(71 rows)

关闭AP加速后，SQL语句的执行计划如下。

关闭AP加速

tpch_10x=# SET rds_duckdb.execution = off;
SET
tpch_10x=# EXPLAIN SELECT
    100.00 * sum(
        CASE WHEN p_type LIKE 'PROMO%' THEN
            l_extendedprice * (1 - l_discount)
        ELSE
            0
        END) / sum(l_extendedprice * (1 - l_discount)) AS promo_revenue
FROM
    lineitem,
    part
WHERE
    l_partkey = p_partkey
    AND l_shipdate >= date '1995-09-01'
    AND l_shipdate < CAST('1995-10-01' AS date);
                                                     QUERY PLAN
--------------------------------------------------------------------------------------------------------------------
 Finalize Aggregate  (cost=1286740.42..1286740.43 rows=1 width=32)
   ->  Gather  (cost=1286739.96..1286740.37 rows=4 width=64)
         Workers Planned: 4
         ->  Partial Aggregate  (cost=1285739.96..1285739.97 rows=1 width=64)
               ->  Parallel Hash Join  (cost=1235166.04..1282419.39 rows=189747 width=33)
                     Hash Cond: (part.p_partkey = lineitem.l_partkey)
                     ->  Parallel Seq Scan on part  (cost=0.00..43232.15 rows=500016 width=29)
                     ->  Parallel Hash  (cost=1233776.40..1233776.40 rows=111171 width=20)
                           ->  Parallel Seq Scan on lineitem  (cost=0.00..1233776.40 rows=111171 width=20)
                                 Filter: ((l_shipdate >= '1995-09-01'::date) AND (l_shipdate < '1995-10-01'::date))
 JIT:
   Functions: 17
   Options: Inlining true, Optimization true, Expressions true, Deforming true
(13 rows)