feat: filter batch by sequence in memtable (#5367)

* feat: add seq field

* feat: filter by sequence

* chore: per review

* docs: explain why not prune

* chore: correct doc

* test: test filter by seq

src/store-api/src/storage/requests.rs

@@ -16,6 +16,8 @@ use common_recordbatch::OrderOption;
 use datafusion_expr::expr::Expr;
 use strum::Display;
 
+use crate::storage::SequenceNumber;
+
 /// A hint on how to select rows from a time-series.
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, Display)]
 pub enum TimeSeriesRowSelector {
@@ -39,4 +41,8 @@ pub struct ScanRequest {
     pub limit: Option<usize>,
     /// Optional hint to select rows from time-series.
     pub series_row_selector: Option<TimeSeriesRowSelector>,
+    /// Optional constraint on the sequence number of the rows to read.
+    /// If set, only rows with a sequence number lesser or equal to this value
+    /// will be returned.
+    pub sequence: Option<SequenceNumber>,
 }