pool00_tmeta and pool00_tdata in lsblk output

I found on one server:

# lsblk

NAME                            MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT

fd0                               2:0    1    4K  0 disk

sda                               8:0    0   50G  0 disk

├─sda1                            8:1    0  500M  0 part /boot

└─sda2                            8:2    0 49.5G  0 part

  ├─vg_oracle002-pool00_tmeta   253:0    0   44M  0 lvm 

  │ └─vg_oracle002-pool00-tpool 253:2    0 41.3G  0 lvm 

  │   ├─vg_oracle002-lv_swap    253:3    0    4G  0 lvm  [SWAP]

  │   ├─vg_oracle002-lv_root    253:4    0 37.3G  0 lvm  /

  │   └─vg_oracle002-pool00     253:5    0 41.3G  0 lvm 

  └─vg_oracle002-pool00_tdata   253:1    0 41.3G  0 lvm 

    └─vg_oracle002-pool00-tpool 253:2    0 41.3G  0 lvm 

      ├─vg_oracle002-lv_swap    253:3    0    4G  0 lvm  [SWAP]

      ├─vg_oracle002-lv_root    253:4    0 37.3G  0 lvm  /

      └─vg_oracle002-pool00     253:5    0 41.3G  0 lvm 

sr0

On other servers there is:

# lsblk

NAME                 MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT