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Contoh
Contoh berikut membuat tabel bernama SALES dalam skema eksternal Amazon Redshift bernama. spectrum Data ada dalam file teks yang dibatasi tab. Klausa PROPERTI TABLE menetapkan properti NumRows ke 170.000 baris.
Bergantung pada identitas yang Anda gunakan untuk menjalankan CREATE EXTERNAL TABLE, mungkin ada izin IAM yang harus Anda konfigurasi. Sebagai praktik terbaik, kami merekomendasikan untuk melampirkan kebijakan izin ke peran IAM dan kemudian menetapkannya ke pengguna dan grup sesuai kebutuhan. Untuk informasi selengkapnya, lihat Identitas dan manajemen akses di Amazon Redshift.
create external table spectrum.sales( salesid integer, listid integer, sellerid integer, buyerid integer, eventid integer, saledate date, qtysold smallint, pricepaid decimal(8,2), commission decimal(8,2), saletime timestamp) row format delimited fields terminated by '\t' stored as textfile location 's3://redshift-downloads/tickit/spectrum/sales/' table properties ('numRows'='170000');
Contoh berikut membuat tabel yang menggunakan JsonSerDe untuk referensi data dalam format JSON.
create external table spectrum.cloudtrail_json ( event_version int, event_id bigint, event_time timestamp, event_type varchar(10), awsregion varchar(20), event_name varchar(max), event_source varchar(max), requesttime timestamp, useragent varchar(max), recipientaccountid bigint) row format serde 'org.openx.data.jsonserde.JsonSerDe' with serdeproperties ( 'dots.in.keys' = 'true', 'mapping.requesttime' = 'requesttimestamp' ) location 's3://mybucket/json/cloudtrail';
Berikut CREATE EXTERNAL TABLE AS contoh menciptakan tabel eksternal nonpartisi. Kemudian ia menulis hasil kueri SELECT sebagai Apache Parquet ke lokasi Amazon S3 target.
CREATE EXTERNAL TABLE spectrum.lineitem STORED AS parquet LOCATION 'S3://mybucket/cetas/lineitem/' AS SELECT * FROM local_lineitem;
Contoh berikut membuat tabel eksternal dipartisi dan termasuk kolom partisi dalam query SELECT.
CREATE EXTERNAL TABLE spectrum.partitioned_lineitem PARTITIONED BY (l_shipdate, l_shipmode) STORED AS parquet LOCATION 'S3://mybucket/cetas/partitioned_lineitem/' AS SELECT l_orderkey, l_shipmode, l_shipdate, l_partkey FROM local_table;
Untuk daftar database yang ada di katalog data eksternal, kueri tampilan SVV_EXTERNAL_DATABASES sistem.
select eskind,databasename,esoptions from svv_external_databases order by databasename;
eskind | databasename | esoptions -------+--------------+---------------------------------------------------------------------------------- 1 | default | {"REGION":"us-west-2","IAM_ROLE":"arn:aws:iam::123456789012:role/mySpectrumRole"} 1 | sampledb | {"REGION":"us-west-2","IAM_ROLE":"arn:aws:iam::123456789012:role/mySpectrumRole"} 1 | spectrumdb | {"REGION":"us-west-2","IAM_ROLE":"arn:aws:iam::123456789012:role/mySpectrumRole"}
Untuk melihat detail tabel eksternal, kueri tampilan SVV_EXTERNAL_TABLES dan SVV_EXTERNAL_COLUMNS sistem.
Contoh berikut menanyakan tampilan SVV_EXTERNAL_TABLES.
select schemaname, tablename, location from svv_external_tables;
schemaname | tablename | location -----------+----------------------+-------------------------------------------------------- spectrum | sales | s3://redshift-downloads/tickit/spectrum/sales spectrum | sales_part | s3://redshift-downloads/tickit/spectrum/sales_partition
Contoh berikut menanyakan tampilan SVV_EXTERNAL_COLUMNS.
select * from svv_external_columns where schemaname like 'spectrum%' and tablename ='sales';
schemaname | tablename | columnname | external_type | columnnum | part_key -----------+-----------+------------+---------------+-----------+--------- spectrum | sales | salesid | int | 1 | 0 spectrum | sales | listid | int | 2 | 0 spectrum | sales | sellerid | int | 3 | 0 spectrum | sales | buyerid | int | 4 | 0 spectrum | sales | eventid | int | 5 | 0 spectrum | sales | saledate | date | 6 | 0 spectrum | sales | qtysold | smallint | 7 | 0 spectrum | sales | pricepaid | decimal(8,2) | 8 | 0 spectrum | sales | commission | decimal(8,2) | 9 | 0 spectrum | sales | saletime | timestamp | 10 | 0
Untuk melihat partisi tabel, gunakan query berikut.
select schemaname, tablename, values, location from svv_external_partitions where tablename = 'sales_part';
schemaname | tablename | values | location -----------+------------+----------------+------------------------------------------------------------------------- spectrum | sales_part | ["2008-01-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-01 spectrum | sales_part | ["2008-02-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-02 spectrum | sales_part | ["2008-03-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-03 spectrum | sales_part | ["2008-04-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-04 spectrum | sales_part | ["2008-05-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-05 spectrum | sales_part | ["2008-06-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-06 spectrum | sales_part | ["2008-07-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-07 spectrum | sales_part | ["2008-08-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-08 spectrum | sales_part | ["2008-09-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-09 spectrum | sales_part | ["2008-10-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-10 spectrum | sales_part | ["2008-11-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-11 spectrum | sales_part | ["2008-12-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-12
Contoh berikut mengembalikan ukuran total file data terkait untuk tabel eksternal.
select distinct "$path", "$size" from spectrum.sales_part; $path | $size --------------------------------------------------------------------------+------- s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-01/ | 1616 s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-02/ | 1444 s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-02/ | 1444
Contoh partisi
Untuk membuat tabel eksternal yang dipartisi berdasarkan tanggal, jalankan perintah berikut.
create external table spectrum.sales_part( salesid integer, listid integer, sellerid integer, buyerid integer, eventid integer, dateid smallint, qtysold smallint, pricepaid decimal(8,2), commission decimal(8,2), saletime timestamp) partitioned by (saledate date) row format delimited fields terminated by '|' stored as textfile location 's3://redshift-downloads/tickit/spectrum/sales_partition/' table properties ('numRows'='170000');
Untuk menambahkan partisi, jalankan perintah ALTER TABLE berikut.
alter table spectrum.sales_part add if not exists partition (saledate='2008-01-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-01/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-02-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-02/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-03-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-03/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-04-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-04/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-05-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-05/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-06-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-06/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-07-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-07/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-08-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-08/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-09-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-09/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-10-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-10/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-11-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-11/'; alter table spectrum.sales_part add if not exists partition (saledate='2008-12-01') location 's3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-12/';
Untuk memilih data dari tabel yang dipartisi, jalankan kueri berikut.
select top 10 spectrum.sales_part.eventid, sum(spectrum.sales_part.pricepaid) from spectrum.sales_part, event where spectrum.sales_part.eventid = event.eventid and spectrum.sales_part.pricepaid > 30 and saledate = '2008-12-01' group by spectrum.sales_part.eventid order by 2 desc;
eventid | sum --------+--------- 914 | 36173.00 5478 | 27303.00 5061 | 26383.00 4406 | 26252.00 5324 | 24015.00 1829 | 23911.00 3601 | 23616.00 3665 | 23214.00 6069 | 22869.00 5638 | 22551.00
Untuk melihat partisi tabel eksternal, kueri tampilan SVV_EXTERNAL_PARTITIONS sistem.
select schemaname, tablename, values, location from svv_external_partitions where tablename = 'sales_part';
schemaname | tablename | values | location -----------+------------+----------------+-------------------------------------------------- spectrum | sales_part | ["2008-01-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-01 spectrum | sales_part | ["2008-02-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-02 spectrum | sales_part | ["2008-03-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-03 spectrum | sales_part | ["2008-04-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-04 spectrum | sales_part | ["2008-05-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-05 spectrum | sales_part | ["2008-06-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-06 spectrum | sales_part | ["2008-07-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-07 spectrum | sales_part | ["2008-08-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-08 spectrum | sales_part | ["2008-09-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-09 spectrum | sales_part | ["2008-10-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-10 spectrum | sales_part | ["2008-11-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-11 spectrum | sales_part | ["2008-12-01"] | s3://redshift-downloads/tickit/spectrum/sales_partition/saledate=2008-12
Contoh format baris
Berikut ini menunjukkan contoh menentukan parameter ROW FORMAT SERDE untuk file data yang disimpan dalam format AVRO.
create external table spectrum.sales(salesid int, listid int, sellerid int, buyerid int, eventid int, dateid int, qtysold int, pricepaid decimal(8,2), comment VARCHAR(255)) ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.avro.AvroSerDe' WITH SERDEPROPERTIES ('avro.schema.literal'='{\"namespace\": \"dory.sample\",\"name\": \"dory_avro\",\"type\": \"record\", \"fields\": [{\"name\":\"salesid\", \"type\":\"int\"}, {\"name\":\"listid\", \"type\":\"int\"}, {\"name\":\"sellerid\", \"type\":\"int\"}, {\"name\":\"buyerid\", \"type\":\"int\"}, {\"name\":\"eventid\",\"type\":\"int\"}, {\"name\":\"dateid\",\"type\":\"int\"}, {\"name\":\"qtysold\",\"type\":\"int\"}, {\"name\":\"pricepaid\", \"type\": {\"type\": \"bytes\", \"logicalType\": \"decimal\", \"precision\": 8, \"scale\": 2}}, {\"name\":\"comment\",\"type\":\"string\"}]}') STORED AS AVRO location 's3://mybucket/avro/sales' ;
Berikut ini menunjukkan contoh menentukan parameter ROW FORMAT SERDE menggunakan. RegEx
create external table spectrum.types( cbigint bigint, cbigint_null bigint, cint int, cint_null int) row format serde 'org.apache.hadoop.hive.serde2.RegexSerDe' with serdeproperties ('input.regex'='([^\\x01]+)\\x01([^\\x01]+)\\x01([^\\x01]+)\\x01([^\\x01]+)') stored as textfile location 's3://mybucket/regex/types';
Berikut ini menunjukkan contoh menentukan parameter ROW FORMAT SERDE menggunakan Grok.
create external table spectrum.grok_log( timestamp varchar(255), pid varchar(255), loglevel varchar(255), progname varchar(255), message varchar(255)) row format serde 'com.amazonaws.glue.serde.GrokSerDe' with serdeproperties ('input.format'='[DFEWI], \\[%{TIMESTAMP_ISO8601:timestamp} #%{POSINT:pid:int}\\] *(?<loglevel>:DEBUG|FATAL|ERROR|WARN|INFO) -- +%{DATA:progname}: %{GREEDYDATA:message}') stored as textfile location 's3://mybucket/grok/logs';
Berikut ini menunjukkan contoh mendefinisikan log akses server Amazon S3 di bucket S3. Anda dapat menggunakan Redshift Spectrum untuk menanyakan log akses Amazon S3.
CREATE EXTERNAL TABLE spectrum.mybucket_s3_logs( bucketowner varchar(255), bucket varchar(255), requestdatetime varchar(2000), remoteip varchar(255), requester varchar(255), requested varchar(255), operation varchar(255), key varchar(255), requesturi_operation varchar(255), requesturi_key varchar(255), requesturi_httpprotoversion varchar(255), httpstatus varchar(255), errorcode varchar(255), bytessent bigint, objectsize bigint, totaltime varchar(255), turnaroundtime varchar(255), referrer varchar(255), useragent varchar(255), versionid varchar(255) ) ROW FORMAT SERDE 'org.apache.hadoop.hive.serde2.RegexSerDe' WITH SERDEPROPERTIES ( 'input.regex' = '([^ ]*) ([^ ]*) \\[(.*?)\\] ([^ ]*) ([^ ]*) ([^ ]*) ([^ ]*) ([^ ]*) \"([^ ]*)\\s*([^ ]*)\\s*([^ ]*)\" (- |[^ ]*) ([^ ]*) ([^ ]*) ([^ ]*) ([^ ]*) ([^ ]*) ([^ ]*) (\"[^\"]*\") ([^ ]*).*$') LOCATION 's3://mybucket/s3logs’;
Berikut ini menunjukkan contoh menentukan parameter ROW FORMAT SERDE untuk data format ION.
CREATE EXTERNAL TABLEtbl_name(columns) ROW FORMAT SERDE 'com.amazon.ionhiveserde.IonHiveSerDe' STORED AS INPUTFORMAT 'com.amazon.ionhiveserde.formats.IonInputFormat' OUTPUTFORMAT 'com.amazon.ionhiveserde.formats.IonOutputFormat' LOCATION 's3://s3-bucket/prefix'
Contoh penanganan data
Contoh berikut mengakses file: spi_global_rankings.csvspi_global_rankings.csv file ke bucket Amazon S3 untuk mencoba contoh-contoh ini.
Contoh berikut menciptakan skema eksternal schema_spectrum_uddh dan databasespectrum_db_uddh. Untukaws-account-id, masukkan ID AWS akun Anda dan role-name masukkan nama peran Redshift Spectrum Anda.
create external schema schema_spectrum_uddh from data catalog database 'spectrum_db_uddh' iam_role 'arn:aws:iam::aws-account-id:role/role-name' create external database if not exists;
Contoh berikut membuat tabel eksternal soccer_league dalam skema schema_spectrum_uddh eksternal.
CREATE EXTERNAL TABLE schema_spectrum_uddh.soccer_league ( league_rank smallint, prev_rank smallint, club_name varchar(15), league_name varchar(20), league_off decimal(6,2), league_def decimal(6,2), league_spi decimal(6,2), league_nspi integer ) ROW FORMAT DELIMITED FIELDS TERMINATED BY ',' LINES TERMINATED BY '\n\l' stored as textfile LOCATION 's3://spectrum-uddh/league/' table properties ('skip.header.line.count'='1');
Periksa jumlah baris dalam soccer_league tabel.
select count(*) from schema_spectrum_uddh.soccer_league;
Jumlah baris ditampilkan.
count 645
Kueri berikut menampilkan 10 klub teratas. Karena klub Barcelona memiliki karakter yang tidak valid dalam string, NULL ditampilkan untuk nama tersebut.
select league_rank,club_name,league_name,league_nspi from schema_spectrum_uddh.soccer_league where league_rank between 1 and 10;
league_rank club_name league_name league_nspi 1 Manchester City Barclays Premier Lea 34595 2 Bayern Munich German Bundesliga 34151 3 Liverpool Barclays Premier Lea 33223 4 Chelsea Barclays Premier Lea 32808 5 Ajax Dutch Eredivisie 32790 6 Atletico Madrid Spanish Primera Divi 31517 7 Real Madrid Spanish Primera Divi 31469 8 NULL Spanish Primera Divi 31321 9 RB Leipzig German Bundesliga 31014 10 Paris Saint-Ger French Ligue 1 30929
Contoh berikut mengubah soccer_league tabel untuk menentukaninvalid_char_handling,replacement_char, dan properti tabel data_cleansing_enabled eksternal untuk menyisipkan tanda tanya (?) sebagai pengganti karakter yang tidak terduga.
alter table schema_spectrum_uddh.soccer_league set table properties ('invalid_char_handling'='REPLACE','replacement_char'='?','data_cleansing_enabled'='true');
Contoh berikut menanyakan tabel soccer_league untuk tim dengan peringkat dari 1 hingga 10.
select league_rank,club_name,league_name,league_nspi from schema_spectrum_uddh.soccer_league where league_rank between 1 and 10;
Karena properti tabel diubah, hasilnya menunjukkan 10 klub teratas, dengan tanda tanya (?) karakter pengganti di baris kedelapan untuk klubBarcelona.
league_rank club_name league_name league_nspi 1 Manchester City Barclays Premier Lea 34595 2 Bayern Munich German Bundesliga 34151 3 Liverpool Barclays Premier Lea 33223 4 Chelsea Barclays Premier Lea 32808 5 Ajax Dutch Eredivisie 32790 6 Atletico Madrid Spanish Primera Divi 31517 7 Real Madrid Spanish Primera Divi 31469 8 Barcel?na Spanish Primera Divi 31321 9 RB Leipzig German Bundesliga 31014 10 Paris Saint-Ger French Ligue 1 30929
Contoh berikut mengubah soccer_league tabel untuk menentukan properti tabel invalid_char_handling eksternal untuk menjatuhkan baris dengan karakter yang tidak terduga.
alter table schema_spectrum_uddh.soccer_league set table properties ('invalid_char_handling'='DROP_ROW','data_cleansing_enabled'='true');
Contoh berikut menanyakan tabel soccer_league untuk tim dengan peringkat dari 1 hingga 10.
select league_rank,club_name,league_name,league_nspi from schema_spectrum_uddh.soccer_league where league_rank between 1 and 10;
Hasilnya menampilkan klub-klub top, tidak termasuk baris kedelapan untuk klubBarcelona.
league_rank club_name league_name league_nspi 1 Manchester City Barclays Premier Lea 34595 2 Bayern Munich German Bundesliga 34151 3 Liverpool Barclays Premier Lea 33223 4 Chelsea Barclays Premier Lea 32808 5 Ajax Dutch Eredivisie 32790 6 Atletico Madrid Spanish Primera Divi 31517 7 Real Madrid Spanish Primera Divi 31469 9 RB Leipzig German Bundesliga 31014 10 Paris Saint-Ger French Ligue 1 30929
