# Pt-online-schema-change results in Redundant argument in printf at /usr/bin/pt-online-schema-change line 3595 for some of my tables

**URL:** <https://forums.percona.com/t/pt-online-schema-change-results-in-redundant-argument-in-printf-at-usr-bin-pt-online-schema-change-line-3595-for-some-of-my-tables/10254>\
**Category:** Percona Toolkit\
**Created:** [April 26, 2021, 8:02pm UTC](https://forums.percona.com/t/pt-online-schema-change-results-in-redundant-argument-in-printf-at-usr-bin-pt-online-schema-change-line-3595-for-some-of-my-tables/10254 "2021-04-26T20:02:53Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![lbrucel](https://avatars.discourse-cdn.com/v4/letter/l/2bfe46/32.png) [@lbrucel](https://forums.percona.com/u/lbrucel)\
**Post date:** [April 26, 2021, 8:02pm UTC](https://forums.percona.com/t/pt-online-schema-change-results-in-redundant-argument-in-printf-at-usr-bin-pt-online-schema-change-line-3595-for-some-of-my-tables/10254/1 "2021-04-26T20:02:53Z")

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I’m trying to alter the character set and collation on all the tables in my database. Some tables work without issue. A number of them fail with \*\*Redundant argument in printf at /usr/bin/pt-online-schema-change line 3595 \*\*

`>pt-online-schema-change --execute --ask-pass --alter "convert to character set utf8mb4 collate utf8mb4_general_ci" D=xxx,t=tbl_conv_state_values,u=xxxx,h=xxxx.us-east-2.rds.amazonaws.com`

Any insight greatly appreciated.

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**Author:** ![lbrucel](https://avatars.discourse-cdn.com/v4/letter/l/2bfe46/32.png) [@lbrucel](https://forums.percona.com/u/lbrucel)\
**Post date:** [April 26, 2021, 9:37pm UTC](https://forums.percona.com/t/pt-online-schema-change-results-in-redundant-argument-in-printf-at-usr-bin-pt-online-schema-change-line-3595-for-some-of-my-tables/10254/2 "2021-04-26T21:37:48Z")

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I’m happy to report that I moved my work over from Ubuntu 16.04 to Ubuntu 18.04 and now the **Redundant argument in printf at /usr/bin/pt-online-schema-change line 3595** error is gone and my tables are altering like a charm.