enterprise geodatabase - What is the significance of the SDE lineage length?

ORA-55378 left a great answer to my question:

Does a high number of SDE_state_lineages slow performance?

But, I realized I don't really understand what lineage length means and how it affects performance? Using the example on this ESRI technical article:

VERSION NAME              LINEAGE LENGTH
------------------------- --------------
TOM.WORKORDER_I0C6531     21
TOM.EDITOR_TB             25
ERIK.WORKORDER_I910313    78
BRENT.DESIGN_F831         92
BRENT.DESIGN_F831_ALT_1   94
BRENT.DESIGN_F831_ALT_2   95

SDE.MAPPING_DEFAULT       138
SDE.LANDBASE              169
SDE.DEFAULT               249
ERIK.EDITOR_EH            275
STEVE.EDITOR_SM           289

What do these lineage lengths actually mean? What is the significance of a length of 289?

Answer

A lineage length of 289 indicates 289 states participate in that lineage. If this is after a compress operation, this indicates there are 289 states that cannot be compressed together to collapse that lineage without affecting the versioned table structure. A likely cause of this is that there are versions that directly reference those states. You can see what state a version currently points to in the sde_versions table.

Edit: If there are active connections, including published map/feature services, there may also be state locks that prevent the compress operation from shrinking the lineage.