# \[Hail 0.2\] Merge two MatrixTable

**URL:** https://discuss.hail.is/t/hail-0-2-merge-two-matrixtable/551
**Category:** Help \[0.1\]
**Created:** [June 22, 2018, 6:48pm UTC](https://discuss.hail.is/t/hail-0-2-merge-two-matrixtable/551 "2018-06-22T18:48:25Z")
**Posts on this page:** 1
**Showing post:** 12

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### Author: ![tpoterba](https://yyz2.discourse-cdn.com/flex036/user_avatar/discuss.hail.is/tpoterba/32/61_2.png) [@tpoterba](https://discuss.hail.is/u/tpoterba)
#### Post date: [November 19, 2019, 10:28am UTC](https://discuss.hail.is/t/hail-0-2-merge-two-matrixtable/551/12 "2019-11-19T10:28:06Z")

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You could certainly implement something with that function, but I think there’s probably no easy way to join 5000 VCFs in this manner right now – it’s essentially a data transpose.

It’s possible that doing a hierarchical `full_outer_join_mt` will perform adequately, as long as it’s broken up into ~2 pipelines (13 merges will be required to get to 5k, by log2(5000)), so doing 6-7 levels in each should work.

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