Composite key pagination support for ghostferry#420
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jameszhu-shopify wants to merge 2 commits intomainfrom
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Composite key pagination support for ghostferry#420jameszhu-shopify wants to merge 2 commits intomainfrom
jameszhu-shopify wants to merge 2 commits intomainfrom
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grodowski
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Dec 16, 2025
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| func (t *TableSchema) paginationKeyColumn(cascadingPaginationColumnConfig *CascadingPaginationColumnConfig) (*schema.TableColumn, int, error) { | ||
| func (t *TableSchema) getPaginationKeyColumns(cascadingPaginationColumnConfig *CascadingPaginationColumnConfig) ([]*schema.TableColumn, []int, error) { |
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Not sure if that's the right place, though all composite columns should be checked for *_bin collation (#422 does this for non-integer PKs in the parent PR)
| @@ -91,6 +92,7 @@ func (c *Cursor) Each(f func(*RowBatch) error) error { | |||
| "tag": "cursor", | |||
| }) | |||
| c.paginationKeyColumn = c.Table.GetPaginationColumn() | |||
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Let's check if this field can be removed 👀
| return t.PaginationKeyColumns | ||
| } | ||
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| // Deprecated: Use GetPaginationKeyIndexes |
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Can we remove the fns that got marked as deprecated?
| } | ||
| } else if cascadingPaginationColumnConfig != nil { | ||
| // Fallback | ||
| if fallbackColumnName, ok := cascadingPaginationColumnConfig.FallbackPaginationColumnName(); ok { |
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I think in case fallback columns are specified that are not the primary key, ghostferry must fail unless there exists a unique index that spans them (in the right order)
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Summary
This PR adds support for tables with composite primary keys (multi-column PKs) in Ghostferry's data migration process. Previously, Ghostferry only supported tables with single-column numeric primary keys. This PR is developed on top of another PR - Pagination beyond uint64
This is a large PR so please let me know if I should break it down to smaller ones.
Key Changes
Core Pagination Key Types (
pagination_key.go)CompositeKeytype: A slice ofPaginationKeyobjects for multi-column keysMinPaginationKey/MaxPaginationKeyfunctions that handle both single and composite keysTable Schema Detection (
table_schema_cache.go)GetPaginationColumns()returns all PK columns (replaces single-columnGetPaginationColumn())Cursor & Data Iteration (
cursor.go,data_iterator.go)(col1, col2) > (?, ?)ORDER BY col1, col2State Management (
state_tracker.go)CompositeKey.NumericPosition()uses first column as heuristic).Verifiers (
iterative_verifier.go,inline_verifier.go,compression_verifier.go)WHERE (k1, k2) IN ((?, ?), ...)Sorter (
data_iterator_sorter.go)MaxPaginationKeySorterhandles mixed key types without panickingTest
✅
dev testpass (unit tests and integration tests)✅ New integration tests are added for composite key support (with 2 columns, 3 columns).
Backward Compatibility