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Bring a local Aedes synapse snapshot up to date

Source: R/synapse-snapshot.R
aedes_update_snapshot.Rd

Saves a new snapshot of the Aedes synapse table at a later time, by applying the edits made since an existing snapshot. Queries at or near the new snapshot time are then fast, since they need few or no CAVE lookups.

Usage

aedes_update_snapshot(
  timestamp = "now",
  from = "latest",
  tag = NULL,
  root = aedes_snapshot_root(),
  rebase = FALSE,
  set = TRUE
)

Arguments

timestamp

The time for the new snapshot: "now" (the default), "latest" for the time of the newest CAVE materialisation version, a POSIXct or a string accepted by as.POSIXct().

from

The snapshot to start from, or "latest" (the default) for the most recent published or full snapshot in root at or before timestamp. Local checkpoints are skipped, so each new one is a single step from a published snapshot.

tag

The name of the new snapshot. Defaults to the timestamp, e.g. "20261001T120000".

root

The snapshot folder. Defaults to aedes_snapshot_root().

rebase

Whether to also save the new snapshot as a full snapshot.

set

Whether to make this the default snapshot for the session.

Value

The result of aedes_use_snapshot() for the new snapshot.

Details

Only synapses on neurons that were edited since from are looked up in CAVE, so updating a day-old snapshot typically takes seconds to minutes. The new snapshot is saved as a checkpoint: a small log.parquet of the synapses whose root ids changed since from (typically about 1 MB per day of edits). Reading a checkpoint combines the logs back to the last full snapshot, which stays fast for months of edits; use rebase = TRUE to also save a full snapshot (about 0.6 GB) that later checkpoints start from.

A timestamp given as a time is rounded down to a whole millisecond (the precision of CAVE edit times).

See also

aedes_use_snapshot()

Examples

if (FALSE) { # \dontrun{
options(aedes.synapse_snapshot_root = "~/data/aedes/syn_snapshot")
aedes_update_snapshot()
aedes_partner_summary("class:DNa", timestamp = "now")
} # }