1.1 billion taxi itinera: CVIII-core ClickHouse botrum portassent

Articuli translatio specialiter pro alumnis curriculi praeparata est Data Engineer.

1.1 billion taxi itinera: CVIII-core ClickHouse botrum portassent

clickhouse fons patens est database columnaris. Magna res est ubi centeni analystae celeriter notitias digerere possunt, sicut decem miliarda novorum monumentorum per diem ingrediuntur. Infrastructura costs ad talem systema sustinendum tam alta esse potuit quam $100 per annum, et potentia dimidium quod secundum consuetudinem. In uno puncto, ClickHouse institutionem ab Yandex Metrica continebat 10 trillion tabularum. Praeter Yandex, ClickHouse etiam successum invenit cum Bloomberg et Cloudflare.

Duo annos exegi comparativus analysis databases machinam unam utens et facta est quam celerrime liberum database software Ego umquam. Cum igitur, tincidunt lineamenta addere non desierunt, subsidium Kafka, HDFS et ZStandard compressionis inclusis. Proximo anno ad modum compressionis cascading subsidium addiderunt, et della-de-delta coding fiebat. Cum comprimendo temporis seriem datam, valores coniecturae bene utens della descriptam comprimi possunt, sed pro calculis melius esset uti delta-by-delta descriptam. Compressio bona facta est clavem ad perficiendi ClickHouse.

ClickHouse constat ex CLXX milibus linearum C++ codice, bibliothecae tertiae factionis exclusis, et una ex minimis datorum codicebas distributa est. Prae SQLite distributionem non adiuvat et consistit in numero 170 milium linearum ex codice C, sicut scriptum est, CCVII fabrum ClickHouse contulerunt et intensio commissorum nuper aucta est.

Mense Martio MMXVII, ClickHouse agere coepit changelog ut facilem evolutionis semitam servet. Etiam documentum monolithicum fasciculum in Markdown substructio hierarchiae fasciculi dimiserunt. Exitus et lineamenta per GitHub investigantur, et generatim programmata multo facilior his paucis annis facta est.

In hoc articulo, inspicere me facturum glomerorum globulorum in AWS EC2 utens 36-core processuum et NVMe repositionis.

UPDATE: Post dies octo postquam primum hanc epistulam evulgavi, probationem meliore configuratione repeto et multo meliores effectus perficio. Haec posta renovata est ad has mutationes cogitandas.

Deductis in AWS EC2 Cluster

Instantias tres c5d.9xlarge EC2 adhibeam in hac positione. Uterque eorum continet 36 virtualis CPUs, 72 GB of RAM, 900 GB of NVMe SSD reposita et subsidia 10 Gigabit retis. $1,962/hora singula in regione occidentali-occidentali, cum currit postulatio, constant. Ego uti Ubuntu Servo 1 LTS ut ratio operativae.

Murus ignis ita configuratur ut quaelibet machina sine restrictionibus inter se communicare possit, et sola mea inscriptio IPv4 a SSH in botro dealbata est.

NVMe claui operational promptitudini status

Pro ClickHouse ad operandum, systema fasciculi in EXT4 forma creabo in NVMe eiectis singulis servientibus.

$ sudo mkfs -t ext4 /dev/nvme1n1
$ sudo mkdir /ch
$ sudo mount /dev/nvme1n1 /ch

Cum omnia configurantur, videre potes punctum montis et 783 GB spatii in unaquaque systemate praesto.

$ lsblk

NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
loop0         7:0    0  87.9M  1 loop /snap/core/5742
loop1         7:1    0  16.5M  1 loop /snap/amazon-ssm-agent/784
nvme0n1     259:1    0     8G  0 disk
└─nvme0n1p1 259:2    0     8G  0 part /
nvme1n1     259:0    0 838.2G  0 disk /ch

$ df -h

Filesystem      Size  Used Avail Use% Mounted on
udev             35G     0   35G   0% /dev
tmpfs           6.9G  8.8M  6.9G   1% /run
/dev/nvme0n1p1  7.7G  967M  6.8G  13% /
tmpfs            35G     0   35G   0% /dev/shm
tmpfs           5.0M     0  5.0M   0% /run/lock
tmpfs            35G     0   35G   0% /sys/fs/cgroup
/dev/loop0       88M   88M     0 100% /snap/core/5742
/dev/loop1       17M   17M     0 100% /snap/amazon-ssm-agent/784
tmpfs           6.9G     0  6.9G   0% /run/user/1000
/dev/nvme1n1    825G   73M  783G   1% /ch

Dataset utar in hoc experimento notitia TUBER quam generavi ex 1.1 miliardis taxi in urbe New York supra sex annos capta. In diarii Unum billion taxi Trips in Redshift singula quomodo collegi hac notitia paro. Reposita sunt in AWS S3, ita AWS CLI configurabo accessibus meis et clavibus secretis.

$ sudo apt update
$ sudo apt install awscli
$ aws configure

Petitionem concurrentem huius ad 100 terminum constituam ut lima citius quam occasus defaltam accipiam.

$ aws configure set 
    default.s3.max_concurrent_requests 
    100

Dataset ex AWS S3 invehitur taxi Faciam et in NVMe primo servo repone. Haec dataset ~104GB in GZIP-CSV forma compressa est.

$ sudo mkdir -p /ch/csv
$ sudo chown -R ubuntu /ch/csv
$ aws s3 sync s3://<bucket>/csv /ch/csv

ClickHouse institutionem

Distributionem OpenJDK pro Java 8 instituam sicut oportet ut Apache ZooKeeper currere, quod ad distributam institutionem ClickHouse in omnibus tribus machinis requiritur.

$ sudo apt update
$ sudo apt install 
    openjdk-8-jre 
    openjdk-8-jdk-headless

Et constitui amet variabilis JAVA_HOME.

$ sudo vi /etc/profile
 
export JAVA_HOME=/usr
 
$ source /etc/profile

Tunc ego systema sarcinarum Ubuntu utar ut strepita de instruam 18.16.1, aspectus et Zookeeper in omnibus tribus machinis.

$ sudo apt-key adv 
    --keyserver hkp://keyserver.ubuntu.com:80 
    --recv E0C56BD4
$ echo "deb http://repo.yandex.ru/clickhouse/deb/stable/ main/" | 
    sudo tee /etc/apt/sources.list.d/clickhouse.list
$ sudo apt-get update

$ sudo apt install 
    clickhouse-client 
    clickhouse-server 
    glances 
    zookeeperd

Directorium pro ClickHouse creabo et etiam configurationem aliquam vincit omnibus tribus servientibus.

$ sudo mkdir /ch/clickhouse
$ sudo chown -R clickhouse /ch/clickhouse

$ sudo mkdir -p /etc/clickhouse-server/conf.d
$ sudo vi /etc/clickhouse-server/conf.d/taxis.conf

Hae figurae vincit me utendo.

<?xml version="1.0"?>
<yandex>
    <listen_host>0.0.0.0</listen_host>
    <path>/ch/clickhouse/</path>

 <remote_servers>
        <perftest_3shards>
            <shard>
                <replica>
                    <host>172.30.2.192</host>
                    <port>9000</port>
                 </replica>
            </shard>
            <shard>
                 <replica>
                    <host>172.30.2.162</host>
                    <port>9000</port>
                 </replica>
            </shard>
            <shard>
                 <replica>
                    <host>172.30.2.36</host>
                    <port>9000</port>
                 </replica>
            </shard>
        </perftest_3shards>
    </remote_servers>

  <zookeeper-servers>
        <node>
            <host>172.30.2.192</host>
            <port>2181</port>
        </node>
        <node>
            <host>172.30.2.162</host>
            <port>2181</port>
        </node>
        <node>
            <host>172.30.2.36</host>
            <port>2181</port>
        </node>
    </zookeeper-servers>

 <macros>
        <shard>03</shard>
        <replica>01</replica>
    </macros>
</yandex>

Curram igitur Zookeeper et servo ClickHouse in omnibus tribus machinis.

$ sudo /etc/init.d/zookeeper start
$ sudo service clickhouse-server start

Discas notitia ut ClickHouse

In prima servo mensam iter creabo (trips) quae schedulam taxi itinerariorum utens machinam Logicam congreget.

$ clickhouse-client --host=0.0.0.0
 
CREATE TABLE trips (
    trip_id                 UInt32,
    vendor_id               String,

    pickup_datetime         DateTime,
    dropoff_datetime        Nullable(DateTime),

    store_and_fwd_flag      Nullable(FixedString(1)),
    rate_code_id            Nullable(UInt8),
    pickup_longitude        Nullable(Float64),
    pickup_latitude         Nullable(Float64),
    dropoff_longitude       Nullable(Float64),
    dropoff_latitude        Nullable(Float64),
    passenger_count         Nullable(UInt8),
    trip_distance           Nullable(Float64),
    fare_amount             Nullable(Float32),
    extra                   Nullable(Float32),
    mta_tax                 Nullable(Float32),
    tip_amount              Nullable(Float32),
    tolls_amount            Nullable(Float32),
    ehail_fee               Nullable(Float32),
    improvement_surcharge   Nullable(Float32),
    total_amount            Nullable(Float32),
    payment_type            Nullable(String),
    trip_type               Nullable(UInt8),
    pickup                  Nullable(String),
    dropoff                 Nullable(String),

    cab_type                Nullable(String),

    precipitation           Nullable(Int8),
    snow_depth              Nullable(Int8),
    snowfall                Nullable(Int8),
    max_temperature         Nullable(Int8),
    min_temperature         Nullable(Int8),
    average_wind_speed      Nullable(Int8),

    pickup_nyct2010_gid     Nullable(Int8),
    pickup_ctlabel          Nullable(String),
    pickup_borocode         Nullable(Int8),
    pickup_boroname         Nullable(String),
    pickup_ct2010           Nullable(String),
    pickup_boroct2010       Nullable(String),
    pickup_cdeligibil       Nullable(FixedString(1)),
    pickup_ntacode          Nullable(String),
    pickup_ntaname          Nullable(String),
    pickup_puma             Nullable(String),

    dropoff_nyct2010_gid    Nullable(UInt8),
    dropoff_ctlabel         Nullable(String),
    dropoff_borocode        Nullable(UInt8),
    dropoff_boroname        Nullable(String),
    dropoff_ct2010          Nullable(String),
    dropoff_boroct2010      Nullable(String),
    dropoff_cdeligibil      Nullable(String),
    dropoff_ntacode         Nullable(String),
    dropoff_ntaname         Nullable(String),
    dropoff_puma            Nullable(String)
) ENGINE = Log;

Tunc extraho et onero singulas tabulas CSV in tabulam triplicem (trips). Sequentia completa est in 55 minutis et 10 secundis. Post hanc operationem, magnitudo directorii notitiae 134 GB erat.

$ time (for FILENAME in /ch/csv/trips_x*.csv.gz; do
            echo $FILENAME
            gunzip -c $FILENAME | 
                clickhouse-client 
                    --host=0.0.0.0 
                    --query="INSERT INTO trips FORMAT CSV"
        done)

Haec summa velocitas 155 MB contenti incompressi CSV per alterum fuit. Suspicor hoc decompressione in GZIP deberi. Posset citius esse ad unzip omnes fasciculos gzipped in parallelis utens xargs et postea data unzipped onerant. Infra descriptio eorum quae in processu CSV importare relata sunt.

$ sudo glances

ip-172-30-2-200 (Ubuntu 16.04 64bit / Linux 4.4.0-1072-aws)                                                                                                 Uptime: 0:11:42
CPU       8.2%  nice:     0.0%                           LOAD    36-core                           MEM      9.8%  active:    5.20G                           SWAP      0.0%
user:     6.0%  irq:      0.0%                           1 min:    2.24                            total:  68.7G  inactive:  61.0G                           total:       0
system:   0.9%  iowait:   1.3%                           5 min:    1.83                            used:   6.71G  buffers:   66.4M                           used:        0
idle:    91.8%  steal:    0.0%                           15 min:   1.01                            free:   62.0G  cached:    61.6G                           free:        0

NETWORK     Rx/s   Tx/s   TASKS 370 (507 thr), 2 run, 368 slp, 0 oth sorted automatically by cpu_percent, flat view
ens5        136b    2Kb
lo         343Mb  343Mb     CPU%  MEM%  VIRT   RES   PID USER        NI S    TIME+ IOR/s IOW/s Command
                           100.4   1.5 1.65G 1.06G  9909 ubuntu       0 S  1:01.33     0     0 clickhouse-client --host=0.0.0.0 --query=INSERT INTO trips FORMAT CSV
DISK I/O     R/s    W/s     85.1   0.0 4.65M  708K  9908 ubuntu       0 R  0:50.60   32M     0 gzip -d -c /ch/csv/trips_xac.csv.gz
loop0          0      0     54.9   5.1 8.14G 3.49G  8091 clickhous    0 S  1:44.23     0   45M /usr/bin/clickhouse-server --config=/etc/clickhouse-server/config.xml
loop1          0      0      4.5   0.0     0     0   319 root         0 S  0:07.50    1K     0 kworker/u72:2
nvme0n1        0     3K      2.3   0.0 91.1M 28.9M  9912 root         0 R  0:01.56     0     0 /usr/bin/python3 /usr/bin/glances
nvme0n1p1      0     3K      0.3   0.0     0     0   960 root       -20 S  0:00.10     0     0 kworker/28:1H
nvme1n1    32.1M   495M      0.3   0.0     0     0  1058 root       -20 S  0:00.90     0     0 kworker/23:1H

Spatium in NVMe liberabo delendo originalis CSV imagini continuando.

$ sudo rm -fr /ch/csv

Convertere ad formam Columna

Log ClickHouse machinam notitias reponunt in forma actuaria ordinantur. Ad data interrogatione citius, eam ad formas columnares utendo machinam MergeTree converto.

$ clickhouse-client --host=0.0.0.0

Sequentia completa est in 34 minutis et 50 secundis. Post hanc operationem, magnitudo indicii notitiae 237 GB ipsius erat.

CREATE TABLE trips_mergetree
    ENGINE = MergeTree(pickup_date, pickup_datetime, 8192)
    AS SELECT
        trip_id,
        CAST(vendor_id AS Enum8('1' = 1,
                                '2' = 2,
                                'CMT' = 3,
                                'VTS' = 4,
                                'DDS' = 5,
                                'B02512' = 10,
                                'B02598' = 11,
                                'B02617' = 12,
                                'B02682' = 13,
                                'B02764' = 14)) AS vendor_id,
        toDate(pickup_datetime)                 AS pickup_date,
        ifNull(pickup_datetime, toDateTime(0))  AS pickup_datetime,
        toDate(dropoff_datetime)                AS dropoff_date,
        ifNull(dropoff_datetime, toDateTime(0)) AS dropoff_datetime,
        assumeNotNull(store_and_fwd_flag)       AS store_and_fwd_flag,
        assumeNotNull(rate_code_id)             AS rate_code_id,

        assumeNotNull(pickup_longitude)         AS pickup_longitude,
        assumeNotNull(pickup_latitude)          AS pickup_latitude,
        assumeNotNull(dropoff_longitude)        AS dropoff_longitude,
        assumeNotNull(dropoff_latitude)         AS dropoff_latitude,
        assumeNotNull(passenger_count)          AS passenger_count,
        assumeNotNull(trip_distance)            AS trip_distance,
        assumeNotNull(fare_amount)              AS fare_amount,
        assumeNotNull(extra)                    AS extra,
        assumeNotNull(mta_tax)                  AS mta_tax,
        assumeNotNull(tip_amount)               AS tip_amount,
        assumeNotNull(tolls_amount)             AS tolls_amount,
        assumeNotNull(ehail_fee)                AS ehail_fee,
        assumeNotNull(improvement_surcharge)    AS improvement_surcharge,
        assumeNotNull(total_amount)             AS total_amount,
        assumeNotNull(payment_type)             AS payment_type_,
        assumeNotNull(trip_type)                AS trip_type,

        pickup AS pickup,
        pickup AS dropoff,

        CAST(assumeNotNull(cab_type)
            AS Enum8('yellow' = 1, 'green' = 2))
                                AS cab_type,

        precipitation           AS precipitation,
        snow_depth              AS snow_depth,
        snowfall                AS snowfall,
        max_temperature         AS max_temperature,
        min_temperature         AS min_temperature,
        average_wind_speed      AS average_wind_speed,

        pickup_nyct2010_gid     AS pickup_nyct2010_gid,
        pickup_ctlabel          AS pickup_ctlabel,
        pickup_borocode         AS pickup_borocode,
        pickup_boroname         AS pickup_boroname,
        pickup_ct2010           AS pickup_ct2010,
        pickup_boroct2010       AS pickup_boroct2010,
        pickup_cdeligibil       AS pickup_cdeligibil,
        pickup_ntacode          AS pickup_ntacode,
        pickup_ntaname          AS pickup_ntaname,
        pickup_puma             AS pickup_puma,

        dropoff_nyct2010_gid    AS dropoff_nyct2010_gid,
        dropoff_ctlabel         AS dropoff_ctlabel,
        dropoff_borocode        AS dropoff_borocode,
        dropoff_boroname        AS dropoff_boroname,
        dropoff_ct2010          AS dropoff_ct2010,
        dropoff_boroct2010      AS dropoff_boroct2010,
        dropoff_cdeligibil      AS dropoff_cdeligibil,
        dropoff_ntacode         AS dropoff_ntacode,
        dropoff_ntaname         AS dropoff_ntaname,
        dropoff_puma            AS dropoff_puma
    FROM trips;

Hoc est quod aspectus output videbatur sicut in operatione;

ip-172-30-2-200 (Ubuntu 16.04 64bit / Linux 4.4.0-1072-aws)                                                                                                 Uptime: 1:06:09
CPU      10.3%  nice:     0.0%                           LOAD    36-core                           MEM     16.1%  active:    13.3G                           SWAP      0.0%
user:     7.9%  irq:      0.0%                           1 min:    1.87                            total:  68.7G  inactive:  52.8G                           total:       0
system:   1.6%  iowait:   0.8%                           5 min:    1.76                            used:   11.1G  buffers:   71.8M                           used:        0
idle:    89.7%  steal:    0.0%                           15 min:   1.95                            free:   57.6G  cached:    57.2G                           free:        0

NETWORK     Rx/s   Tx/s   TASKS 367 (523 thr), 1 run, 366 slp, 0 oth sorted automatically by cpu_percent, flat view
ens5         1Kb    8Kb
lo           2Kb    2Kb     CPU%  MEM%  VIRT   RES   PID USER        NI S    TIME+ IOR/s IOW/s Command
                           241.9  12.8 20.7G 8.78G  8091 clickhous    0 S 30:36.73   34M  125M /usr/bin/clickhouse-server --config=/etc/clickhouse-server/config.xml
DISK I/O     R/s    W/s      2.6   0.0 90.4M 28.3M  9948 root         0 R  1:18.53     0     0 /usr/bin/python3 /usr/bin/glances
loop0          0      0      1.3   0.0     0     0   203 root         0 S  0:09.82     0     0 kswapd0
loop1          0      0      0.3   0.1  315M 61.3M 15701 ubuntu       0 S  0:00.40     0     0 clickhouse-client --host=0.0.0.0
nvme0n1        0     3K      0.3   0.0     0     0     7 root         0 S  0:00.83     0     0 rcu_sched
nvme0n1p1      0     3K      0.0   0.0     0     0   142 root         0 S  0:00.22     0     0 migration/27
nvme1n1    25.8M   330M      0.0   0.0 59.7M 1.79M  2764 ubuntu       0 S  0:00.00     0     0 (sd-pam)

In ultimo experimento plures columnae sunt conversi et recalculi. Aliquod harum functionum non amplius laborandum inveni in hac dataset exspectatione. Ad hanc quaestionem solvendam, functiones indebitas sustuli et notitias oneravit sine conversione ad rationes magis granulares.

Distributio data per botri

Notitiam distribuam per omnes tres nodos botri. Incipere, infra mensam super tribus machinis creabo.

$ clickhouse-client --host=0.0.0.0

CREATE TABLE trips_mergetree_third (
    trip_id                 UInt32,
    vendor_id               String,
    pickup_date             Date,
    pickup_datetime         DateTime,
    dropoff_date            Date,
    dropoff_datetime        Nullable(DateTime),
    store_and_fwd_flag      Nullable(FixedString(1)),
    rate_code_id            Nullable(UInt8),
    pickup_longitude        Nullable(Float64),
    pickup_latitude         Nullable(Float64),
    dropoff_longitude       Nullable(Float64),
    dropoff_latitude        Nullable(Float64),
    passenger_count         Nullable(UInt8),
    trip_distance           Nullable(Float64),
    fare_amount             Nullable(Float32),
    extra                   Nullable(Float32),
    mta_tax                 Nullable(Float32),
    tip_amount              Nullable(Float32),
    tolls_amount            Nullable(Float32),
    ehail_fee               Nullable(Float32),
    improvement_surcharge   Nullable(Float32),
    total_amount            Nullable(Float32),
    payment_type            Nullable(String),
    trip_type               Nullable(UInt8),
    pickup                  Nullable(String),
    dropoff                 Nullable(String),

    cab_type                Nullable(String),

    precipitation           Nullable(Int8),
    snow_depth              Nullable(Int8),
    snowfall                Nullable(Int8),
    max_temperature         Nullable(Int8),
    min_temperature         Nullable(Int8),
    average_wind_speed      Nullable(Int8),

    pickup_nyct2010_gid     Nullable(Int8),
    pickup_ctlabel          Nullable(String),
    pickup_borocode         Nullable(Int8),
    pickup_boroname         Nullable(String),
    pickup_ct2010           Nullable(String),
    pickup_boroct2010       Nullable(String),
    pickup_cdeligibil       Nullable(FixedString(1)),
    pickup_ntacode          Nullable(String),
    pickup_ntaname          Nullable(String),
    pickup_puma             Nullable(String),

    dropoff_nyct2010_gid    Nullable(UInt8),
    dropoff_ctlabel         Nullable(String),
    dropoff_borocode        Nullable(UInt8),
    dropoff_boroname        Nullable(String),
    dropoff_ct2010          Nullable(String),
    dropoff_boroct2010      Nullable(String),
    dropoff_cdeligibil      Nullable(String),
    dropoff_ntacode         Nullable(String),
    dropoff_ntaname         Nullable(String),
    dropoff_puma            Nullable(String)
) ENGINE = MergeTree(pickup_date, pickup_datetime, 8192);

Tunc faciam ut primus minister videat omnes tres nodos in botro.

SELECT *
FROM system.clusters
WHERE cluster = 'perftest_3shards'
FORMAT Vertical;
Row 1:
──────
cluster:          perftest_3shards
shard_num:        1
shard_weight:     1
replica_num:      1
host_name:        172.30.2.192
host_address:     172.30.2.192
port:             9000
is_local:         1
user:             default
default_database:
Row 2:
──────
cluster:          perftest_3shards
shard_num:        2
shard_weight:     1
replica_num:      1
host_name:        172.30.2.162
host_address:     172.30.2.162
port:             9000
is_local:         0
user:             default
default_database:

Row 3:
──────
cluster:          perftest_3shards
shard_num:        3
shard_weight:     1
replica_num:      1
host_name:        172.30.2.36
host_address:     172.30.2.36
port:             9000
is_local:         0
user:             default
default_database:

Tum primum servo novam mensam definiam quae schemate innititur trips_mergetree_third and uses the Distributed engine.

CREATE TABLE trips_mergetree_x3
    AS trips_mergetree_third
    ENGINE = Distributed(perftest_3shards,
                         default,
                         trips_mergetree_third,
                         rand());

Tunc exscribam notitias de MergeTree substructa mensa omnibus tribus servientibus. Sequentia completa sunt in 34 minutis et 44 secundis.

INSERT INTO trips_mergetree_x3
    SELECT * FROM trips_mergetree;

Post operationem supra, XV minuta dedi ClickHouse ut amoveret a maximo gradu repono notae. Notitia directoria finita sunt in 15 GB, 264 GB et 34 GB respective ad unumquemque trium servientium.

ClickHouse botrum portassent perficientur iudicium

Quod proximum videbam erat tempus quam celerrime currentem singulas interrogationes in mensa pluries vidi trips_mergetree_x3.

$ clickhouse-client --host=0.0.0.0

Sequentia peracta 2.449 secundis.

SELECT cab_type, count(*)
FROM trips_mergetree_x3
GROUP BY cab_type;

Sequentia peracta 0.691 secundis.

SELECT passenger_count,
       avg(total_amount)
FROM trips_mergetree_x3
GROUP BY passenger_count;

Sequentia in 0 secundis perficitur.

SELECT passenger_count,
       toYear(pickup_date) AS year,
       count(*)
FROM trips_mergetree_x3
GROUP BY passenger_count,
         year;

Sequentia peracta 0.983 secundis.

SELECT passenger_count,
       toYear(pickup_date) AS year,
       round(trip_distance) AS distance,
       count(*)
FROM trips_mergetree_x3
GROUP BY passenger_count,
         year,
         distance
ORDER BY year,
         count(*) DESC;

Ad comparationem, has interrogationes de MergeTree fundata mensa cucurri, quae solum in primo servo residet.

Euismod aestimatio unius nodi ClickHouse

Quod proximum videbam erat tempus quam celerrime currentem singulas interrogationes in mensa pluries vidi trips_mergetree_x3.

Sequentia peracta 0.241 secundis.

SELECT cab_type, count(*)
FROM trips_mergetree
GROUP BY cab_type;

Sequentia peracta 0.826 secundis.

SELECT passenger_count,
       avg(total_amount)
FROM trips_mergetree
GROUP BY passenger_count;

Sequentia peracta 1.209 secundis.

SELECT passenger_count,
       toYear(pickup_date) AS year,
       count(*)
FROM trips_mergetree
GROUP BY passenger_count,
         year;

Sequentia peracta 1.781 secundis.

SELECT passenger_count,
       toYear(pickup_date) AS year,
       round(trip_distance) AS distance,
       count(*)
FROM trips_mergetree
GROUP BY passenger_count,
         year,
         distance
ORDER BY year,
         count(*) DESC;

Cogitationes de eventibus

Hoc primum est quod gratuita CPU-fundata datorum possibilitatem datorum GPU fundatorum in probationibus meis formare potuit. Quod GPU-fundatur database duas emendationes ab eo tempore pervasit, sed perficiendi quod ClickHouse in uno nodo traditum est, nihilominus valde infigo est.

Eodem tempore, cum Query 1 in machina distributa exequens, supra caput gratuita sunt, ordo magnitudinis superior. Spero me aliquid desiderari in investigatione mea pro hac cursore, quia pulchrum esset videre interrogationes temporum descendentes sicut plures nodos ad botrum addidi. Sed magnum est quod, cum alias interrogationes exequens, effectus per circa 2 tempora augetur.

Pulchrum esset videre evolutionis ClickHouse versus posse reposita separare et computare ut independenter scandere possint. HDFS subsidium, quod proximo anno adiectum est, gradus ad hunc esse potuit. In terminis computandi, si una quaestio accelerari potest additis nodis ad botrum, tunc futura huius programmatis clarissima est.

Wisi enim ad minim tempus legere hoc post. Consultationem, architecturam, et praxim evolutionis clientium in America Septentrionali et Europa officia praebeo. Si disputare velis quomodo suggestiones meae negotium tuum adiuvare possunt, pete me per contactum Quantcast.

Source: www.habr.com