These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.23 s (backtrack: 0/20).

[ebuild  N     ] dev-libs/lzo-2.10:2::gentoo  USE="(split-usr) -examples -static-libs" 587 KiB
[ebuild  N     ] dev-libs/libaio-0.3.113_p8::gentoo  USE="-static-libs -test" 74 KiB
[ebuild  N     ] acct-group/mysql-0-r3::gentoo  0 KiB
[ebuild  N     ] acct-group/nagios-0-r3::gentoo  0 KiB
[ebuild  N     ] app-arch/lz4-1.10.0-r1:0/1.10.0-meson::gentoo  USE="-static-libs -test" 379 KiB
[ebuild  N     ] sys-libs/liburing-2.15:0/2::gentoo  USE="-examples -static-libs -test" 538 KiB
[ebuild  N     ] dev-db/mysql-connector-c-8.0.41-r1:0/21::gentoo  USE="-ldap -static-libs" 477295 KiB
[ebuild  N     ] acct-user/mysql-0-r3::gentoo  0 KiB
[ebuild  N     ] acct-user/nagios-0-r3::gentoo  0 KiB
[ebuild  N     ] dev-db/mariadb-connector-c-3.4.9-r2:0/3::gentoo  USE="curl -gnutls -kerberos -static-libs -test" 1352 KiB
[ebuild  N     ] dev-perl/DBD-mysql-5.13.0::gentoo  USE="mysql -mariadb -test" PERL_FEATURES="ithreads (-debug) -quadmath" 157 KiB
[ebuild  N     ] dev-db/mysql-init-scripts-2.3-r8::gentoo  0 KiB
[ebuild  N     ] dev-perl/DBD-MariaDB-1.240.0::gentoo  USE="mariadb -minimal -mysql -test" PERL_FEATURES="ithreads (-debug) -quadmath" 185 KiB
[ebuild  N     ] dev-db/mariadb-12.3.3-r1:12.3/18::gentoo  USE="backup pam perl server -aws-km -bindist -columnstore -cracklib -debug -extraengine -galera -innodb-lz4 -innodb-lzo -innodb-snappy -jdbc -jemalloc -kerberos -latin1 -mroonga -numa -odbc -oqgraph -profiling -rocksdb -s3 (-selinux) -sphinx -sst-mariabackup -sst-rsync -static (-systemd) -systemtap -tcmalloc -test -xml -yassl" 217709 KiB
[ebuild  N     ] virtual/mysql-8.0:0/18::gentoo  USE="server -static" 0 KiB
[ebuild  N     ] net-analyzer/ndoutils-2.1.4::gentoo  2138 KiB

Total: 16 packages (16 new), Size of downloads: 700409 KiB