Merge #141213 #141392 #141446

141213: sql: enable tenant testing for schema_changer tests r=cthumuluru-crdb,rafiss a=shubhamdhama

Previously all tests in this file were disabled for multitenancy.

(Continuation of #140447 for `schema_changer_test.go`)

Informs: #140446
Epic: CRDB-38970
Release note: None

141392: sqlstats: Reuse sessionphase.Times on stats collector r=xinhaoz a=xinhaoz

StatsCollector.Reset shows up in sqlstats section of cpu/mem
profiles. This seemed to mostly be allocations of new session.PhaseTimes
objects. This commit avoids new allocations of session.PhaseTimes
when resetting the stats collector.

Epic: none

Release note: None

```
name                                           old time/op    new time/op    delta
Sysbench/SQL/3node/oltp_read_write-24            13.2ms ± 2%    13.0ms ± 1%  -1.69%  (p=0.001 n=10+10)
ParallelSysbench/SQL/3node/oltp_read_write-24    1.22ms ± 3%    1.22ms ± 1%    ~     (p=0.315 n=10+10)

name                                           old errs/op    new errs/op    delta
Sysbench/SQL/3node/oltp_read_write-24              0.00           0.00         ~     (all equal)
ParallelSysbench/SQL/3node/oltp_read_write-24      0.01 ±20%      0.01 ±52%    ~     (p=0.231 n=9+10)

name                                           old alloc/op   new alloc/op   delta
Sysbench/SQL/3node/oltp_read_write-24            2.18MB ± 1%    2.18MB ± 1%    ~     (p=0.666 n=9+9)
ParallelSysbench/SQL/3node/oltp_read_write-24    2.03MB ± 1%    2.03MB ± 1%    ~     (p=0.971 n=10+10)

name                                           old allocs/op  new allocs/op  delta
Sysbench/SQL/3node/oltp_read_write-24             10.5k ± 2%     10.5k ± 2%    ~     (p=0.529 n=10+10)
ParallelSysbench/SQL/3node/oltp_read_write-24     9.16k ± 2%     9.17k ± 2%    ~     (p=0.853 n=10+10)
```


141446: backup: fix panic on encrypted incremental after non-encrypted backup r=msbutler a=kev-cao

When attempting an encrypted backup on a non-encrypted backup chain, an error should be surfaced to the user indicating an error and inability to do so. Due to a missing error check, this currently panics.

Epic: none

Release note: None

Co-authored-by: Shubham Dhama <[email protected]>
Co-authored-by: Xin Hao Zhang <[email protected]>
Co-authored-by: Kevin Cao <[email protected]>

Author: 4 people

pkg/backup/backupencryption/encryption.go

@@ -363,6 +363,9 @@ func GetEncryptionFromBaseStore(
 		return nil, nil
 	}
 	opts, err := ReadEncryptionOptions(ctx, baseStore)
+	if err != nil {
+		return nil, err
+	}
 	var encryptionOptions *jobspb.BackupEncryptionOptions
 	switch encryptionParams.Mode {
 	case jobspb.EncryptionMode_Passphrase: