target-postgres - Meltano Hub

PostgreSQL

target-postgres from datamill-co

PostgreSQL database loader

The target-postgres Meltano loader pulls data from PostgreSQL that can then be sent to a destination using a loader.

Other Available Variants

datamill-co
meltano
meltanolabs
transferwise (default)

Getting Started

Prerequisites

If you haven't already, follow the initial steps of the Getting Started guide:

Dependencies

target-postgres requires the libpq library to be available on your system. If you've installed PostgreSQL, you should already have it, but you can also install it by itself using the libpq-dev package on Ubuntu/Debian or the libpq Homebrew formula on macOS.

Installation and configuration

Add the target-postgres loader to your project using
```
meltano add
```
:

meltano add loader target-postgres --variant datamill-co

Configure the target-postgres settings using
```
meltano config
```
:

meltano config target-postgres set --interactive

Next steps

Follow the remaining steps of the Getting Started guide:

Run a data integration (EL) pipeline

If you run into any issues, learn how to get help.

Troubleshooting

Error: `psycopg2.ProgrammingError: syntax error at or near "-"`

This error message indicates that the extractor you are using this loader with generates stream names that include the source database schema in addition to the table name: <schema>-<table>, e.g. public-accounts. This is not supported by this variant of target-postgres.

Instead, use the transferwise variant which was made to be used with extractors that behave this way.

Error: `pg_config executable not found` or `libpq-fe.h: No such file or directory`

This error message indicates that the libpq dependency is missing.

To resolve this, refer to the "Dependencies" section above.

`ld`, `clang`, `lssl`, or `linker` Errors

If you have an error message like:

ld: library not found for -lssl
clang: error: linker command failed with exit code 1
error: command 'clang' failed with exit status 1

These error messages indicates that there is a problem installing OpenSSL.

This Stack Overflow answer has specific recommendations on setting the LDFLAGS and/or CPPFLAGS environment variables. Set those prior to running meltano add loader target-postgres.

Capabilities

The current capabilities for

target-postgres

may have been automatically set when originally added to the Hub. Please review the capabilities when using this loader. If you find they are out of date, please consider updating them by making a pull request to the YAML file that defines the capabilities for this loader.

This plugin has the following capabilities:

You can override these capabilities or specify additional ones in your meltano.yml by adding the capabilities key.

Settings

The target-postgres settings that are known to Meltano are documented below. To quickly find the setting you're looking for, click on any setting name from the list:

You can override these settings or specify additional ones in your meltano.yml by adding the settings key.

Please consider adding any settings you have defined locally to this definition on MeltanoHub by making a pull request to the YAML file that defines the settings for this plugin.

Host (postgres_host)

Environment variable: TARGET_POSTGRES_POSTGRES_HOST
Default Value: localhost

[No description provided.]

Port (postgres_port)

Environment variable: TARGET_POSTGRES_POSTGRES_PORT
Default Value: 5432

[No description provided.]

Database (postgres_database)

Environment variable: TARGET_POSTGRES_POSTGRES_DATABASE

[No description provided.]

Username (postgres_username)

Environment variable: TARGET_POSTGRES_POSTGRES_USERNAME

[No description provided.]

Password (postgres_password)

Environment variable: TARGET_POSTGRES_POSTGRES_PASSWORD

[No description provided.]

Schema (postgres_schema)

Environment variable: TARGET_POSTGRES_POSTGRES_SCHEMA
Default Value: $MELTANO_EXTRACT__LOAD_SCHEMA

Note that $MELTANO_EXTRACT__LOAD_SCHEMA will expand to the value of the load_schema extra for the extractor used in the pipeline, which defaults to the extractor's namespace, e.g. tap_gitlab for tap-gitlab.

Name of the schema where the tables will be created. If schema_mapping is not defined then every stream sent by the tap is loaded into this schema.

SSL Mode (postgres_sslmode)

Environment variable: TARGET_POSTGRES_POSTGRES_SSLMODE
Default Value: prefer

Refer to the libpq docs for more information about SSL.

SSL Cert (postgres_sslcert)

Environment variable: TARGET_POSTGRES_POSTGRES_SSLCERT
Default Value: ~/.postgresql/postgresql.crt

Only used if a SSL request w/ a client certificate is being made

SSL Key (postgres_sslkey)

Environment variable: TARGET_POSTGRES_POSTGRES_SSLKEY
Default Value: ~/.postgresql/postgresql.key

Only used if a SSL request w/ a client certificate is being made

(postgres_sslrootcert)

Environment variable: TARGET_POSTGRES_POSTGRES_SSLROOTCERT
Default Value: ~/.postgresql/root.crt

Used for authentication of a server SSL certificate

SSL CRL (postgres_sslcrl)

Environment variable: TARGET_POSTGRES_POSTGRES_SSLCRL
Default Value: ~/.postgresql/root.crl

Used for authentication of a server SSL certificate

Invalid Records Detection (invalid_records_detect)

Environment variable: TARGET_POSTGRES_INVALID_RECORDS_DETECT
Default Value: true

Include false in your config to disable target-postgres from crashing on invalid records

Invalid Records Threshold (invalid_records_threshold)

Environment variable: TARGET_POSTGRES_INVALID_RECORDS_THRESHOLD
Default Value: 0

Include a positive value n in your config to allow for target-postgres to encounter at most n invalid records per stream before giving up.

Disable Collection (disable_collection)

Environment variable: TARGET_POSTGRES_DISABLE_COLLECTION
Default Value: false

Include true in your config to disable Singer Usage Logging.

Logging Level (logging_level)

Environment variable: TARGET_POSTGRES_LOGGING_LEVEL
Default Value: INFO

The level for logging. Set to DEBUG to get things like queries executed, timing of those queries, etc.

Persist Empty Tables (persist_empty_tables)

Environment variable: TARGET_POSTGRES_PERSIST_EMPTY_TABLES
Default Value: false

Whether the Target should create tables which have no records present in Remote.

Max Batch Rows (max_batch_rows)

Environment variable: TARGET_POSTGRES_MAX_BATCH_ROWS
Default Value: 200000

The maximum number of rows to buffer in memory before writing to the destination table in Postgres

Max Buffer Size (max_buffer_size)

Environment variable: TARGET_POSTGRES_MAX_BUFFER_SIZE
Default Value: 104857600

The maximum number of bytes to buffer in memory before writing to the destination table in Postgres. Default: 100MB in bytes

Batch Detection Threshold (batch_detection_threshold)

Environment variable: TARGET_POSTGRES_BATCH_DETECTION_THRESHOLD

How often, in rows received, to count the buffered rows and bytes to check if a flush is necessary.

There's a slight performance penalty to checking the buffered records count or bytesize, so this controls how often this is polled in order to mitigate the penalty. This value is usually not necessary to set as the default is dynamically adjusted to check reasonably often.

State Support (state_support)

Environment variable: TARGET_POSTGRES_STATE_SUPPORT
Default Value: true

Whether the Target should emit STATE messages to stdout for further consumption.

In this mode, which is on by default, STATE messages are buffered in memory until all the records that occurred before them are flushed according to the batch flushing schedule the target is configured with.

Add Upsert Indexes (add_upsert_indexes)

Environment variable: TARGET_POSTGRES_ADD_UPSERT_INDEXES
Default Value: true

Whether the Target should create column indexes on the important columns used during data loading.

These indexes will make data loading slightly slower but the deduplication phase much faster. Defaults to on for better baseline performance.

Before Run SQL (before_run_sql)

Environment variable: TARGET_POSTGRES_BEFORE_RUN_SQL

Raw SQL statement(s) to execute as soon as the connection to Postgres is opened by the target. Useful for setup like SET ROLE or other connection state that is important.

After Run SQL (after_run_sql)

Environment variable: TARGET_POSTGRES_AFTER_RUN_SQL

Raw SQL statement(s) to execute as soon as the connection to Postgres is opened by the target. Useful for setup like SET ROLE or other connection state that is important.

Something missing?

This page is generated from a YAML file that you can contribute changes to.

Edit it on GitHub!

Looking for help?

If you're having trouble getting the target-postgres loader to work, look for an existing issue in its repository, file a new issue, or join the Meltano Slack community and ask for help in the