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Single-Table Migration Tool - mxgate

Starting from version 4.3, MatrixGate supports migration mode, enabling high-speed data migration from Greenplum 5, Greenplum 6, and YMatrix clusters into the current YMatrix cluster.

1 High-Speed Migration Principle

High-speed migration allows data to bypass the Master node. Data is read directly from the source cluster's Segments, forwarded through mxgate, and sent directly to the target cluster's Segments. This eliminates the bottleneck of a single Master node.

The number of Segments in the source and target clusters can differ.

2 Usage

2.1 Single-Table Migration

Single-table migration transfers all data from a specified table. Example usage:

mxgate --source transfer \
         --src-host 172.31.41.7 \
         --src-port 5432 \
         --src-db postgres \
         --src-user ec2-user \
         --src-password abc \
         --src-schema public \
         --src-table trans_ao \
         --compress "gzip" \
         --port-base 9129 \
         --local-ip 172.31.33.128 \
         --db-database ttt \
         --target public.trans_ao \
         --format text \
         --time-format raw \
         --use-auto-increment=false

Parameters:

Parameter	Description
--source	Functional entry point; must be set to 'transfer'
--src-host	IP address of the source cluster's master
--src-port	Port number of the source cluster's master
--src-user	Username for connecting to the source database (superuser is recommended)
--src-password	Connection password
--src-schema	Schema name of the source table
--src-table	Name of the source table
--compress	Data transfer method from source segment hosts to this machine: Empty string `""`: no compression, plain text transfer `gzip`: use gzip compression; requires the `gzip` Linux command installed on source segment hosts `lz4`: use lz4 compression; requires the `lz4` Linux command installed on source segment hosts Recommended order: lz4 > gzip > no compression
--port-base	Range of ports used during transfer starts from 9129
--local-ip	Must be an IP address reachable from the source cluster
--db-database	Target database name where the destination table resides
--target	Target table name in the format `<schema>.<table>`; if schema is omitted, defaults to `public`
--format	`text` or `csv`. Use `csv` only when data contains complex strings (e.g., newlines, quotes, delimiters). Otherwise, prefer `text`
--time-format	Must be `raw` in transfer mode
--use-auto-increment	By default, mxgate skips serial auto-increment columns in the target table. Use this option to disable that behavior

2.2 Export to File

Another use of migration mode is to quickly export data to files:

mxgate --source transfer \
         --src-host 172.31.41.7 \
         --src-port 5432 \
         --src-db postgres \
         --src-user ec2-user \
         --src-schema public \
         --src-table trans_ao_1 \
         --compress "lz4" \
         --port-base 9129 \
         --local-ip 172.31.33.128 \
         --save-to-dir /tmp/receive/ \
         --db-database ttt \
         --transform nil \
         --writer nil \
         --target trans_ao

Use the --save-to-dir parameter to specify the file storage path.

Note: Even when exporting to files, you must provide --db-database and --target to specify the target database and table, and the target database and table must exist.

2.3 Filtered Migration

Filtered migration uses the --src-sql parameter to specify a SQL query that filters the data to be migrated. This works for both table-to-table and table-to-file migrations:

mxgate --source transfer \
         --src-host 172.31.41.7 \
         --src-port 5432 \
         --src-db postgres \
         --src-user ec2-user \
         --src-sql "select * from demo where c1 = 'xxxx'" \
         --compress "lz4" \
         --port-base 9129 \
         --local-ip 172.31.33.128 \
         --save-to-dir /tmp/receive/ \
         --db-database ttt \
         --transform nil \
         --writer nil \
         --target trans_ao

For a complete list of mxgate migration tool parameters, see mxgate.

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Migration Approach

Full-database Migration - mxshift